Period question!!! (please answer)?

So my last period was December 22nd and it lasted 7 days. I started bleeding again the day i was suppose to have ovulated (which was 2 weeks after the period) and i had unprotected sex that same day. Actually right after the sex i started spotting. That lasted from January 8th through 15th. Not heavy just spotting. I took pregnancy tests but all negative. Around the time my periods are suppose to start i just have cramping but no blood. It is now almost April and no period. Anyone have a clue of what's happening???