16 days dpo- IUI

So we had an IUI procedure two weeks ago yesterday and i was told take a test. I’ve been testing since five days before and they have all been negative. Well for the last 3 days I’ve had a headache and it’s the type of headache I had when I was taking the hormones. I’ve also only been testing first thing in the morning and that’s it. Should I test at night too? My doctors office just told me to rest at the end of the week and go from there. This was our first IUI. The next one will be with a trigger shot if this one has failed.

I don’t get headaches during my period and I barely have period symptoms.