Safe for 2nd round of clomid?

My cycles are crazy irregular, but going off an avg 28 day cycle (which I never have) I'm 11 days late. This last cycle is the most regular cycle I've ever had with provera/ clomid. Never caught a positive opk but other symptoms seemed positive. All bfns so far.

Now I have round 2 of provera/clomid ready to start. But glow says my fertile week starts wed! I've been feeling mild cramping and tender nipples for about a week. So idk if it's af or maybe really going to ovulate!?

My question really is how long is a safe waiting period with no period before starting round 2. I've read so many awful stories of clomid while pregnant I want to be extra sure I'm not, but hate losing time. I'm also going on Vaca in 23 days.

Any insight appreciated!