Contraception

Hi all! I have had the nexplannon implant in since march. Recently i have been getting stomach pains/cramps almost but no period.
Do you think this is just a sign my period is coming? Or could it be a sign of something else? I normally waken in the morning and feel sick until i eat or drink. My last period was about 2 months ago and its been my only period from i got the implant :/
Thanks!