Possible Early Miscarriage?

My DH and I have officially been ttc for the last few months. I originally thought that it wouldn't be too difficult- go off the birth control and then a month or two tops we'd be on our way.

Unfortunately nothing has gone so simply. For the last few months I have been tracking my period and BBT and last month I began tracking ovulation. My cycle for the last 5 months have been 30 days exactly. I was charting my BBT sporadically and testing ovulation every day. My period for this month was scheduled to start on the 25th of january. In the previous months I was never really able to detect any changes in my CM, but this month I noticed "egg-white" on the 16th and the 17th. I also took ovulation tests and it was positive both days (days 22 & 23 of my cycle). My husband and I BD'd on the 15th and again on the 17th. My BBT on the 18th also shot up .8 of a degree.

I tested on the 24th which was the day that my period was due and it was BFN. On the 25th I experienced the sharp prick that I usually get an hour or two before my AF makes it's appearance, but nothing showed. Same pain on the 26th accompanied by my typical period cramping but again nothng and no sign of AF. I had no nausea or constipation but a lot of bloating and gas. I tested again on the 26th and again BFN. Tested again on the 29th and BFN. Finally late yesterday (the 30th) I had some cramps followed by my typcial period flow.

I'm really confused because my period has not been that late before and I hadn't changed any patterns (same stress, diet and everything). I really feel that I could have been pregnant but because I ovulated so late the HCG wasn't high enough in my bloodstream yet. I was thinking that sharp pains around my period time could have been from implantation, but I'm really not sure.

Totally depressed and bummed over this. Does anyone have any thoughts or similar experiences?