Threw up after high BJ...help...

So.. I was giving my hubby a BJ and he was in a little deeper than "normal" and he was really enjoying it-then he started finishing and something started triggering my gag reflex- I tried to stop it but when he pulled out because he was done I grabbed for a spare towel and ended up throwing up a bit. I really didn't want to -mentally I was enjoying myself I just couldn't stop that gag reflex. Has this happened to anybody else and does anyone have any tips for me? I don't know if it made a difference but I am also 29 weeks pregnant and I feel like my stomach has more stomach acid stuff that wants to rise up to the surface more easily...