Life after nexplanon

Okay so I got my nexplanon inserted 7/13/17 but due the side affects I had it removed 1/12/18. I got my period 1/29/18, according to my 'Flo' app I ovulated 2/8/18 & sex 2/9/18. Is it possible I could be pregnant? Since 2/12/17 I have been having sore breast. Today (2/20/18) I experienced little cramps but nothing painful. Oh I've also been testing and all negative, but I feel pregnant. I don't know I feel like it's all in my head, app says I should get my period Friday but idk who accurate that is since I've only been off my birth control for a little over a month.