PLEASE HELP! Ovidril causing false negative?

Jessica
Today is CD 25 for me, and last month AF cam a couple of days early because of the ovidril I took. I took ovidril again this month on CD 10 and <a href="https://glowing.com/glow-fertility-program">IUI</a> on CD 12. I should get AF tomorrow but I have no symptoms and I just "feel" different. I've had cramping this week, but it doesn't feel exactly like period cramping.  I took a test this morning because I am impatient, but it was negative.
Is it possible this is a false negative due to the ovidril medicine still in my system? Or is it still too early to tell?