Is Scanty Blood During Menstruation A Symptom Of Pregnancy?

I have a very light period, not enough blood to even fill a panty liner. I m worried, but I also hope it s a sign of pregnancy. I just did a home test and it almost looks negative, because you can barely see the second line (it s there, but very faint) My period started out very bright pink red colored and that was 3 days ago, now it s red brown with no blood clots at all. I always have a regular cycle with heavy flow and dark red blood clots. I am on birth control pills, but I missed taking in a few times. On the day I was ovulating according to calendar, I forgot to take it in and had sex that day and 2 days before that. Should I keep taking my birth control pills or is that causing the faint positive? And how long should I wait until I do another home pregnancy test?