If i've been on birth control for over 6 months and take it correctly, and he pulls out, does it mean a delayed period means i am pregnant?

Likely not: Do you mean birth control pills? When taken correctly, at the same time every day, the pill has a failure rate <1%. Withdrawal alone has a much higher failure rate, but the 2 methods together have a low rate of failure to prevent pregnancy. If, by a "delayed period" your mean, a missed period, it can occur due to the pill. Check a pregnancy test to be sure, and if negative, keep taking the pills.