Regular or irregular period?

Okay so I been off from BC since November 2014 haven't gotten pregnant. Between then and now I took some prenatal pills just for a couple of weeks then I stopped. Anywho, my question is.... My period was on point starting January through March (only 3 months lol) but it was on point always on the 13th I missed April so I thought I was pregnant but May came and I actually got my period on the 22nd then I got it July 1st... 
I don't know if I'm regular (at least I was) but now what's happening!?!?!? Ugh, kinda frustrating... :-/
T.I.A.!