I think perhaps you're doing the right thing going to the docs. They can lance and drain the boil for you, then pack it with something other than, well, pus! What you don't want is for it to get so big that an operation is required. That sounds extreme but actually, my ex husband once had one that, under the skin (and he was a slim guy) it got to the size of a lemon - all you could see on the outside was a red, hot and painful area. We ended up going to the ER because he had developed a blood infection from "stuff" getting into his bloodstream and then he had to have emergency surgery!
Not to scare you, but, that can sometimes happen. So yeah I'd get to the docs and see if they can basically extract what's inside. Antibiotics may be prescribed but, you know, they can prescribe ones that won't do harm to your baby and in the end, if it gets very bad that might interfere worse than antibiotics would have, ya know?