pregnant w/o ovulation??

I started my infertility medications again last month (femara and progesterone). My day ten progesterone level was miniscule, less than 0.5, meaning no chance of ovulation. fast forward to Tuesday, don't get my period. Took a pregnancy test and as soon as I finished going on it, the plus showed up. My doc has me doing hcg blood levels every 48 hours now, my first one was 393. After all the troubles we had conceiving #2, I'm having a hard time actually believing this. How is this possible to have no signs of ovulation but to still be pregnant?