I had an abortion and still haven't gotten my period. i just got the nexplanon and i had unprotected sex on the 7th day after getting it planted. could i be pregnat?

Unlikely: Nexplanon is one of the most effective pregnancy prevention methods there is. Its highly unlikely that you are pregnant. Nexplanon will keep you from having regular periods and that is probably why you didn't have a period. For peace of mind, you might want to do a test but after awhile you will become accustomed to life without regular periods. Best wishes!