Would love anyones input!

I have been ttc for three years now. I did 100 mg of clomid in October and got positive opk. Then I went and had cd 21 blood work done and was told by my doctor I didn't ovulate...I was crushed! I have not had a natural period in probably over a year but my period was due yesterday and I started bleeding! Even though I was upset about apparently not ovulating, I was a little excited to get my period on my own. Long story short... yesterday and today I have only had a little brown when I wipe ever now and again. I have cramping and my boobs are killing me. Is my period just trying to come? Or implantation bleeding? Ectopic? I'm very confused and worried.... I worry way too much! Any advise would be appreciated!