Period's late, but negative home pregnancy test: Could I be pregnant?

By JustMommies staff

Your period is late, you're having pregnancy symptoms, but you are still getting a negative pregnancy test. Could you still be pregnant? If you're not pregnant, why is your period late and what should you do about it?




Some basic physiology

Your menstrual cycle is divided into two phases. The first half is called the follicular phase and lasts from the start of menstruation until ovulation. The second half is called the luteal phase and starts at ovulation extending outward until pregnancy or until menstruation begins again. During the follicular phase of your cycle you will produce hormones, specifically LH (luteinizing hormone) and FSH (follicle stimulating hormone). After ovulation occurs it triggers a rise in a second set of hormones, progesterone and estrogen. The length of the follicular phase can vary greatly. The luteal phase, from ovulation onward, is typically 13 to 14 days. So let's say a woman's typical cycle is the standard 28 days, but for this cycle our hypothetical woman's follicular phase is 16 days instead of her typical 14 days. This would mean if she tested the day her period was "due", she would actually be testing at 12 days past ovulation verses what she is assuming to be 14 days. The two day difference could be the difference between a negative and a positive pregnancy test.

Pregnancy tests and implantation


Other causes for a pregnancy test to not detect pregnancy


Are you pregnant? Find out your due date with JM's Due Date Calculator.