*really good* chance that you could be pregnnat per your description. If you are trying to get pregnant, you certainl;y can, but if you don't want to, then you are sure exposing yourself to a lot of risk. *anytime* you have any kind of sex without a condom, you risk pregnancy, and certainly if you actually have intercourse, the sperm can be carried in pre-cum. As such, even if he doesn't ejaculate, you could be pregnant.
It is a pretty safe assumption that if you have sex without a condom or other contraception, you can almost certainly assume yourself pregnant, if not the first time, then certainly within to long.
The choice is all yours, but it is a very safe assumption that:
unprotected sex=pregnancy.