OK Im 15, My ex is 14,and it hasnt even been a week since we broke up...the day we broke up she got back?

OK Im 15, My ex is 14,and it hasnt even been a week since we broke up...the day we broke up she got back with her ex...the day before we broke up we had sex and she said her period was almost over. The Condom DID NOT break and I was very carefull about this to avoid prgnancy. We have previously broke up before and shes used the whole "im pregnant" trick to get me back. I think shes doing the same thing again because she keeps tellin me she wants me back but i said screw you because you left me after dating for a long time for another guy the same day we break up? After we had sex about a day later she told me she took 5 pregnancy tests and said they all read pregnant. Me I personaly belive that she took the test too early I just want to know people opinions about this situation. P.S. She has ADD ODHD and she is adopted..her real mom was on drugs and she dont even know her real dad...I personaly belive that she is just immature and playing with me she isnt very smart I think she has mental problems hope this situation makes somebody laugh lol