am I crazy?

I have been having some weird things going on with my body and Im not sure what to chalk it up to. I got my BC (Nexplanon) out Feb 6 after having it in for 3 years. Doc said to expect period within 4-6 weeks, so I wasn't surprised when I started bleeding March 12th; however, I was surprised it was really light. I would wake up to small amount of blood when I wiped but by 8 am I wasn't bleeding anymore and didn't until the next morning. The bleeding continued until the 15th, with the same pattern of bleeding everyday. On the 16th I started having a clear sticky discharge so I took an ovulation test and it said positive. Since then I've had symptoms on and off sore breasts, fatigue, nausea, itchy nipples, and for the last couple of days I have felt a sort of flutter in my lower abdomen. I'm just wondering if these are signs of early pregnancy and I'm not crazy! I took a test last night and it was negative.