so I had an abortion 5 weeks ago and I got the implanon the same day, I was told to wait 2 weeks before sex again but I had sex 4 days later unprotected... could I be pregnant?

Any time you have sex there is always some possibility of becoming pregnant. Of course being pregnant/having an abortion could have thrown your cycle off too. Play it safe, take a test and find out for sure. And next time when the doctor says no sex, listen!