Letrozole

Hi, so we’ve been TTC for almost two years and I got what I thought was period 9 days ago. They started me back on letrozole on day 3. I took a test two days before my period started and it was negative.

I never have my period this long so on a whim I took a pregnancy test and it came up super positive! (Yay!) but can that be from the letrozole and has anyone taken letrozole not knowing they were pregnant and had a healthy baby? I’m like double freaking out over here!