Trying to Conceive after birth control

[hollyblucher]

I went off of the birth control patch in May (about 4 months ago) and my periods have been extremely irregular. I of course got a normal period in May when I removed my last patch. I didn't get a period again until July 21st, and I have not had a period since then. We are currently trying to conceive baby #2, but I have no way of knowing when I'm ovulating. I looked into temping and OPK's, but both say not to start until you have your period. I have been trying to gauge ovulation by my CM and the way I feel, but I feel like my body is just going complete haywire. I thought I was going through my "fertile" window of time toward the end of last week/over the weekend, but then last evening I started having cramps in my lower abdomen and my lower back. I even had some mild cramping when I woke up this morning so I assumed that my period was coming. However, still no period. I've read that some women get pregnant weeks after going off of birth control and some women can take over a year. Does anyone have any advice on tracking ovulation with irregular periods? Could my cramping possibly be caused by implantation even though I believe I just ovulated 3-5 days ago? It's so frustrating that PMS/early pregnancy symptoms are so similar!