Took Provera, but still no period!?

Good Morning Ladies, I had a doctor's appointment on January 26th and was given Provera to start my period and then Clomid to take once my period starts. I took Provera for 10 days, and now here I am 8 days after taking the last pill and still no period (I've had cramping but no blood). I took a negative hpt a couple days ago so I know that's not it. I know it can take up to two weeks after taking the last pill for your period to start but what's weird is that I've taken Provera 3 times before now and EVERY time I woke up on the third day after the last pill with a period. Has anyone else had a similar experience? I'm anxious to start my second round of clomid and just want this stupid period to start! ugh!