How to Get Pregnant when Having Irregular Periods

Ask the Expert with Dr. Don Aptekar

Timing is everything when it comes to getting pregnant. Timing your fertile window and getting pregnant, however, can be challenging if you have irregular periods. Priya met with seasoned expert in fertility, Dr. Don Aptekar, to answer commonly asked questions about trying to conceive with irregular cycles. Dr. Aptekar founded Partners in Women's Health and has helped thousands of women get pregnant over the past 40 years. 

Read the Q&A below to get the scoop on the most common questions asked by women trying to get pregnant when they go to see Dr. Aptekar. 



  • You don't need to wait- talk to your doctor if you have any questions or concerns about your period and trying to conceive.
  • Track your menstrual cycles and how heavy or light they are. If you go to see your doctor, your doctor will need data on your last 4-6 menstrual cycles.
  • Pinpoint if you are ovulating and your most fertile window.
  • Relax and try to have fun with the process.


Q: I’m not sure but I think I may have an irregular period. What is the definition of an irregular period?

A:  Great question. A regular period is 28 days plus or minus 7 days. So in other words, you have an irregular period if it is shorter than every 21 days or longer than 35 days (to read more, check out this article).


Q: What is the main concern with irregular periods when trying to conceive?

A:  The main concern when trying to get pregnant is to determine whether or not you are ovulating. Having irregular periods can mean several things and it’s best to track your period and talk to your healthcare provider to discuss your individual case. That said, irregular periods may indicate that there is a hormonal imbalance or it could also be due to diet or stress.


Q: Will having irregular periods make it harder for me to get pregnant?

A: Here is how I answer that question- If you ovulate regularly then you may have 13 chances in a year to get pregnant. If your period is every 40 days then you only have 10 times a year to try and therefore it could take more time but not always. If you can pinpoint the days you ovulate and plan intercourse it may not take you any longer.


Q: Do I need to see a doctor because my periods are irregular?

A:  I recommend that if your periods are 45-60 days that you see a healthcare professional. As always, however, you should see your healthcare professional anytime if you have questions as they can be a great resource to answer any concerns you may have.  


Q: A friend told me to have intercourse every other day while TTC- do we need to be doing that? 

A: My concern with this method is that you will make yourself crazy and start to hate the process. To keep from making yourself crazy and have your relationship suffer, I recommend not making having a baby a task. The best way to get pregnant is to figure out with precision when you ovulate. Outside of your fertile window, you should have intercourse when you want to.

If you do decide to have intercourse every other day or every day, hopefully your husband or partner won’t start calling in sick(!).   

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Q: I’ve heard that our chances of getting pregnant go down if we have sex in less than 48 hours due to sperm count dropping?

A: While there is some science showing that having intercourse everyday will lower the sperm count a little, this is ONLY relevant if your partner has a low sperm count to begin with (note: new research shows that saving sperm up is actually unhelpful. Check it out here). If someone has a normal sperm count, then this is irrelevant. Like the question before this one, I tell my patients to try and enjoy the process. Enjoy the spontaneity and don’t make trying to conceive a task.

If your partner does have a lower sperm count, however, then wait 48 hours. Also, optimize the precision to hit ovulation. That way it is fine to abstain for 2-3 days before and you won’t miss the optimal time.


Q: Do I need to take fertility drugs?

A: If you are ovulating, you don’t need to take fertility drugs. Fertility drugs will often shorten the process but the risk is multiple births. Fertility drugs encourage the body to make more eggs. So if you don’t want twins or triplets, then wait to find out if you are ovulating first. If you pinpoint your fertile window and when you ovulate, you will increase your chances greatly getting pregnant naturally.


Q: I have polycystic ovary syndrome (PCOS) does that mean I can’t have a baby? 

A: Many women with PCOS conceive on their own but it may take longer. If you have been diagnosed with PCOS, you may only ovulate 3-4 times a year.

There are also other  medical conditions such as diabetes and hypertension that may be associated with PCOS.  If you have concerns you should ask your healthcare professional. In some cases medication can assist you.

Q: What is the best method to predict ovulation for irregular periods to increase my chances of getting pregnant?

A: If you have a regular menstrual cycle, ovulation normally happens two weeks (14 days) before your next period.  You want to get busy during your fertile window which is 4-5 day prior to ovulation and the day of ovulation. This is only a guess based on averages and may leave you wondering if you are missing your optimal time or not. If you can find your biomarkers by using methods such as  BBT charts, LH sticks and cervical mucus, with out getting you stressed out, go for it. 


Q: What information will my doctor need to know about my period?

A: If you go to see your doctor about trying to conceive, they are going to ask you about your shortest and longest period to get more information about whether or not you are ovulating. Information doctors typically need are the length of your last 4-6 cycles and whether or not your period was heavy or light.

They also will use this information to help you calculate when you are most fertile.

Keep in mind that if you and/or your doctor calculate your fertile window based on the length of your menstrual cycles, it is a statistical prediction not an actual one.


In Summary:

Dr. Aptekar’s advice is to have fun and make the process less tedious if you can. He strongly advises, however, that if you have very irregular cycles and have any concerns, that you should see your doctor. You need to find out if you are ovulating. 

Also, don’t forget that the issue may not be you, but could also be your partner. If you are over 35 and have been trying for 6 months or if you are under 35 and have been trying for 12 months, you should also have your partner get checked. When a couple is infertile, it is 30% due to the man and 30% due to the woman.  The remaining causes are due to both partners or unexplained infertility.

Otherwise, if you know that you are ovulating, in the words of Dr. Aptekar, “it may take longer than you expected so be prepared for that and have fun with the process."