By: Kacie Shrock, RN, BSN | Oct 24, 2022
If you have been trying to conceive, odds are you have researched the difference between PMS and pregnancy symptoms a time or two as they are very similar! It’s normal to pay extra close attention to every symptom and sensation during the two week wait in an attempt to determine if they are related to your period coming or if they are signs of early pregnancy.
Premenstrual syndrome (PMS) is a group of symptoms linked to the menstrual cycle that can start about 1-2 weeks before your period. These symptoms are caused by hormonal changes in Progesterone and Estrogen.
The comparison between PMS and pregnancy symptoms
Often, these symptoms can mirror early pregnancy symptoms, which makes it tricky to determine the source while you wait to take a pregnancy test.
Let’s take a closer look at the symptoms of each:
Two Pregnancy Specific Symptoms
There is a chance we could differentiate early pregnancy from PMS through 2 unique symptoms – nausea and a missed period.
While there are many common symptoms between PMS and pregnancy, one tell-tale sign you may be pregnant is nausea/vomiting. Nausea and vomiting are typically not common with PMS, however some gastrointestinal symptoms like constipation/diarrhea may be. Nausea and vomiting, better known as morning sickness during pregnancy, can be one of the first noticeable signs of pregnancy for some and tend to last throughout the first trimester. However, morning sickness typically doesn’t begin until week 6 of pregnancy.
Missed period -
The biggest sign that you may be pregnant? A missed period. PMS is followed by the start of your period, so a missed period is a great indicator of early pregnancy. If your period is delayed, grab a pregnancy test!
Not everyone will experience early pregnancy symptoms before their missed period, however nearly 90% of women will experience pregnancy symptoms by 8 weeks gestation. So, if you are in your two week wait and have an absence of symptoms, that doesn't mean that there is still not a chance of pregnancy, there absolutely could still be a chance!
The only way to tell the difference between PMS and early pregnancy is if your period arrives or not and if that pregnancy test is positive!
Remember, you want to wait until at least 12-14 DPO (days past ovulation) before you take a pregnancy test to prevent any possible false negative results. If you test too early, you may not catch hCG levels as it can take a few days for it to reach levels high enough in your urine to show positive on a pregnancy test.
If you are experiencing severe PMS or pregnancy symptoms, always discuss these with your healthcare provider as there may be a way to help relieve your symptoms.
Have more questions about possible symptoms during your two week wait? Head over to Ask An Expert and submit your question to one of our medical advisors to be answered within 24 business hours!
Nurse Kacie is a registered nurse who specializes in fertility and reproductive health. She has always had a passion for women's health and she supports women and couples virtually across the world while on their journey to their dream families!
Bai G, Korfage IJ, Groen EH-de, Jaddoe VWV, Mautner E, Raat H. Associations between nausea, vomiting, fatigue and health-related quality of life of women in early pregnancy: The Generation R Study. PLOS ONE. https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0166133.
Yonkers KA, O'Brien PMS, Eriksson E. Premenstrual syndrome. Lancet (London, England). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3118460/. Published April 5, 2008.
DD; SAEWAJWCRB. A prospective study of the onset of symptoms of pregnancy. Journal of clinical epidemiology. https://pubmed.ncbi.nlm.nih.gov/12160915/#:~:text=Nearly%2090%25%20of%20women%20with,6%20weeks)%20are%20sometimes%20symptomatic.