Letrozole/ Femera Question

I’ve been on Letrozole/ Femera for 4 months now. The first three months, I ovulated around cd 14 or 15, and my period started on day 28. I didn’t take it last month, and my period started around day 34. This month, I got my positive on the 24th, which was cycle day 12. I haven’t gotten my period yet, and I’m on day 33. We’ve been trying for over a year and a half, and I don’t want to take a test too early and get disappointed when I could’ve avoided it. Has this happened to anyone when they were taking it?