Welcome to HCM and thanks for posting
From your description it looks like you are having cellulitis
(infection of the hypodermis) which can be due to bacteria such as strep, staph, pseudomonas
etc. You will need a course of antibiotics that is both effective for skin infection
and safe for your unborn baby. You can pay a visit to a gynobs who can do a proper evaluation and provide you with appropriate mediation. Pain killers will also be needed.
Hope this helps