So I am driving myself crazy

trying to figure out if I am pregnant and this Digital Clearblue test is just evil or if I'm not and the Levothyroxine I started taking a month ago is the reason my cycle is messed up.
Up until today, my cycles have been quite regular. One month was rather early at 26 days but mostly they are 27-28 days. My husband and I are TTC. By estimation, I should have ovulated around the 25th of Dec. and we tried on that day. Last week on Thursday, 11 DPO, I had some cramping, no bleeding (impantation cramps?). I have also been extremely tired even though I sleep a lot. The cramping has been off and on since then in my lower abdomin. They sort of feel like AF cramps, but not as intense... Normally I have really bad cramps when she is around. My period was due on Monday, the 9th.
This morning, being 3 days late and still no bleeding, I took a Clearble Digital test. It was negative. I took a FRER test 3 days ago (day before my before my period was due) and it also was negative. This afternoon however I started having some light bleeding.
So I have 2 questions....#1 has anyone had a false negative result using the Digital Clearblue? #2 Has anyone been on Levothyroxine for Hypothyroidism and had it mess with their cycle?
Any info would be appreciated! Thanks!