Due to misuse of the pill due to antibiotics and a busy schedule I thought I could be pregnant and went off the pill a few days after unprotected sex. Days after going off the pill I had an on/off withdrawl bleed if dark brown mucus over 2 days and then 2-3 drops of light brown spotting 2 days after that. My normal period is bright red blood and last 5 days consistently. I've had pregnancy symptons and am waiting a few more days to get accurate result from HPT. Could I be pregnant even though I had a withdrawl bleed? I've heard it's not a "true" period just the body releasing old blood due to the absence of a hormone in the pill?

There is no form of birth control that is 100% effective. Anytime a penis is inserted into a vagina pregnancy is a risk.

You are now playing the waiting game and have to wait to see if your period comes as expected. If not, wait 2 weeks then test using first morning urine.