Early pregnancy signs ???

I've been charting my bbt this cycle.. at the beginning of my cycle my bbt was 97.05.. after what I think was a + opk my bbt went to 98.12. I'm predicted to start my period in a few days and my bbt is continuing to stay in the high 97 and low 98. I am also experiencing very full/swollen/sore breasts and nipples.. I am really hoping there will be a BFP! It very well could be a fluke but here's to hoping! Any advice or comments, ladies ?