April 2016 I got the Nexplanon bar implant. The first few months made me have a period constantly and then became regular once my body got used to it. I always had a period.

April 2019, I got the old one out and a new one put back in. My boyfriend and I waited to have sex for three weeks just to give my body time to fully adjust to the new bar. We have had sex a few times since then but we don't use condoms. (please no hate)

My period is almost three weeks late this month. I have tiny bits of spotting every now and then. I took two pregnancy tests just to make sure, both came out negative.

My question is: can the second round of birth control effect your body differently than first time? Should I be worried? Should I take another test?