Carry on with sex. The only reason to stop is if the doctor tells you that there are complications with your pregnancy and that you should not have intercourse. This does not happen that often though.
Remember, that there are other forms of sex that do not include penetration, if that makes you feel better.
Otherwise, have fun, enjoy yourself. There is absolutely no reason to stop. I never did and I had 4 babies. I had intercourse up to the night before I delivered.
Sex is healthy

. Sex is good for you

, it is good for your relationship

. Enjoy yourself now before you are up all night and tired when he wants to.