Could Bleeding Between Periods Mean Heavier Implantation Bleeding?

i usually take birthcontrol, but i was off of it for about 2 months and then i went back on. i had been taking it for about a week when i had sex. i had had my period a week or so before and was starting to ovulate when we had sex. about three days later i started bleeding. i have been bleeding for about 5 days now and it is odd because i have always gotten my period exactly on time and it has never been off. this period wasnt heavy, but it wasnt light either. i usually have extremely heavy and extremely painful periods, but there was no pain with this either. it has pretty much stopped now and i was just wondering if this could be some heavier implantation bleeding or if it is something else.