I've been on the birth control Nexplanon implant for 3 months now. When I first got the implant I had spotting and periods. But now no spotting and no periods. I took a pregnancy test just to make sure I wasn't pregnant. And it didn't show anything, the pregnancy test was blank which means invalid. So I'm not pregnant. Has this happened to anyone else? Should I wait until next month to see if my period comes? Should I be worried or happy?