Need help!

I am on the Nexplanon and have been long enough for it to be effective (got it April 10th) and my period was supposed to start today according to <a href="">Eve</a>, but it has been wrong before and I know the implant can effect my period, yesterday morning my boyfriend came in me and I just need reasurence that I am far from the possibility of getting pregent. I have been having terrible cramps for the last four days so I know something is going on in there!