Pulling out method

So I've been with my boyfriend for almost 2 years now and we used to use condoms and I used to be on BC but every kind I tried made me super sick and made my periods horrible! So we have been using the pull out method for a looong time, he swears he knows exactly when he's going finish and always says there's no reason to worry cause he is for sure about it..we have never had any scares or anything but it scares the shit out of me..anyone else use this method!?