I'm not sure...

Af was supposed to be here Friday or Saturday. I am not sure how many days between ovulation. Since my last miscarriages I have been pretty irregular. Well af still has not started. I woke up feeling so bloated and it hurts like a gas bubble. But more sharp and comes on waves... I tested on Saturday and it was a bfn... when should I try again. Or should I just wait... tia! :)