How are you doing ?
As long as the swelling are not causing any pain or signs of infection or bleeding, you better leave it alone. Once you complete the delivery , the swelling can be taken care of.
This swelling if in the interior of vagina , may just be congested veins in vagina, which appears towards the end of pregnancy
. The head of baby presses on the veins & make it more prominent. Once baby is delivered , the pressure is released & swelling will disappear on it's own. You don't need anything more
Other possibility is retention cyst
, in vagina due to collection of secretions. this can be cleared during delivery.
Last possibility is Bartholin's cyst or abscess
. This is usually at the opening of vagina. This will need treatment only if painful or infected. If not it can be corrected during delivery
Hope I have clarified your query, do write back if any further queries
All the best