I Have Irregular Periods. I Had My Last Period On

I have irregular periods. I had my last period on March 22, and the one before that on February 13. I had sex with my boyfriend in the evening on April 12 and he used a condom. Late in the evening on Wednesday the 15th night I had bright red spotting. On Thursday morning I spotted then did not spot again until that evening. Friday the 17tg I spotted off and on throughout the day. The color was maroonish. I guess slightly darker than normal? I didn't spot any on Saturday the 18th through Sunday the nineteenth but today (Monday the 20th) my spotting came back and it's pink but it's much more than it was before. Based on the fact I have longer cycles anyway, is there a possibility this was ovulation or premenstrual bleeding rather than implantation bleeding? It seems like it began too early on Wednesday to be implantation. And the fact that it completely stopped for two days then started again makes me think that this is something else. I also have had a headache off and on when I'm bleeding and my breasts have hurt but only on Thursday and today. I'm also noticing some dizziness and nausea today. It feels like my usual period because I'm very emotional but I read that you can confuse implantation with your normal period.