Not sure what to do!

I haven’t had a period since July 12th! I’ve took multiple test over the last few weeks all negative. I had my nexplanon removed August 3rd. We have had sex several times since. Still nothing! I use to take the same birth control for 6 years and was regular to the week and day every month! I knew the week before I took a test I was pregnant. That was over 3 years ago when I got pregnant with my son. He’s going to be 3 in December! When we decided to get pregnant with him I didn’t start another pack of pills after my period ended and was pregnant before the next cycle. Now I haven’t been regular with this nexplanon and not sure if I should just keep waiting or go see my doctor!