2 day period?!

Ok, ladies! I have been on birth control for about 2 years now and my periods are always very consistent. They typically* start on Wednesday's and end by Saturday or Sunday nights. This last cycle my period started on Thursday and ended Saturday. It was very short and mostly brown blood! I did fill a couple of tampons, but that was it. I haven't been too consistent with taking my birth control- within the same 5-6 hours everyday, but I haven't been having sex either. I did have intercourse once earlier this month, but he entered once and I told him to stop because I didn't want it. I was 10 hours late on my first pill of the month. Obviously there is probably a chnace that I could be pregnant, but do you think it's likely?!?! Is the fact that my period was so short a sign?! I'm really stressing! I've been reading other girls posts and most say a 2 day period is not a sign of a period and most of them turned out pregnant! Any advice or info on this? D: