Bleeding after FET

TW: pregnancy

I’m 5wks 3 days. Betas were: 25 at 8 dpt, 101 at 11 dpt then 773 at 15 dpt. Yesterday I had a small amount of brown spotting. It stopped mid morning. This morning I had dark red blood (not brown), enough to totally fill toilet paper when I wiped, then it stopped and now is constant dark brown or light pink spotting whenever I wipe. I recently switched from PIO to PEO 3 days ago. Could this be related? Has anyone experienced anything similar and gone on to find out everything is ok? I’m waiting on beta + progesterone results from bloodwork this morning. My clinic won’t do an ultrasound until 2/18.