BC help please!!

Okay so this may be slightly confusing? But I was off birth control for about 5 days all on my fertile week and realized I was getting off of my BC in the middle of the cycle and didn't want to throw it off so I started to take my pills again, just until next week for my expected period so I can sill be on track. The thing is, I've taken a couple tests with very faint positives.. Waiting to test again until next Tuesday. If I am pregnant is it harmful at this early stage to still be taking BC pills? I only have a few pills left but if it's harmful I want to stop taking them right now! Please help!