could be pregnant????

I am on the pill and take it at the same time EVERY NIGHT, no mishaps. My boyfriend came inside me on September 28th and then again on October 5th. I was due for my period on October 8th, it came on time (as usual) but was just very like dark brown spotting for 3 days which is totally not my normal period. There were a couple clots of dark brown blood but I’m scared it could’ve been implantation bleeding even though it came on the day my period comes. If this was considered a “missed period” I would be 8 days late or more if you count the whole sugar pill week. I’ve taken 5 tests all negative including a digital one. Thoughts? Thank you!!!!