Help please! (Tmi)

My husband and I have been trying for over 2 years I have PCOS something. You're never regular but my last period was kind of a rest dark brown color and that lasted one day then my husband and I BD and after sex I realize that I was bleeding so I thought it was the start of my period but then the next day it stopped and I haven't had a period in like 4 days then tonight me and my husband BD I noticed I was bleeding a little bit but not enough to put a pad or tampon I'm worried because I've never bled during sex before and I don't know if I should go to the doctor or take a test I haven't taken a test and I'm about 15 days late and I'm nervous because every time I take when it's negative and it makes me really upset and depressed and I just don't want to be disappointed once again? Thank you for your advise