Yes, certainly your options are limited for patients that are pregnant or nearly pregnant. In fact, there are only two medications that are considered Class B, or generally regarded safe in pregnancy.
One of those is called Finacea, or azelaic acid. And the second one is Clindamycin, which is a topical antibiotic. We don't have any oral options for patients that are nearly pregnant or pregnant.
We do have these couple topical options that are decent for use in acne, and they can be very helpful to decrease the pimples due to the bacteria that cause acne (p. acnes). Azelaic acid and Clindamycin are a good place to start. Please discuss these with your dermatologist prior to use.