Infected insect bite in pregnancy? Safe to take oral antibiotics?

Depends on type. This is something your primary physican or ob/gyn doctor can determine. There are references that tell which drugs are safe in pregnancy which the doc can use as needed.
See below. Treatment with the usual antibiotics for cellulitis would be safe.

Related Questions

Is an infected insect bite dangerous in pregnancy?

Not necessarily. Pregnancy is always tricky and needs careful care with your gynecologist. Treatment for infection requires careful choice for efficacy and toxicity, and you have to do this carefully with people are pregnant. Read more...

How to numb the pain of my infected insect bite besides a hot towel and aspirin?

It may need Drainage. You need to see a physician. If you're having that much pain then i would be worried you have an abscess and this needs to be drained and then given antibiotics. Read more...
Heat = worse. If it is an acute bite, then cool or cold compresses will relieve it, heat will make it worse. If it's been there a few days, and now it's painful or oozing, see your doctor. Read more...