Unsure

Back in October I found out I was pregnant. My boyfriend and I talked about keeping the baby but niether of us are done with school and are not finically stable so we decided not to keep the baby and I had an abortion. ( please not judgment, it is something I regret everyday but I can't take it back) I went back on birth control a week later and waited about 3 weeks to have sex. We had unprotected sex and he came in me more than once. Birth control has always worked for me no issues. I haven't had my period since before I got pregnant and I'm starting to get worried. Could I be pregnant again?