My labia minora is swollen after sex. is this normal?

No, but it happens: If the sex is too rough, too long, too dry etc, the labia minora can become inflamed. It is not normal, but it is not uncommon. Using extra lubricant such as astroglide or pjur can help. Allergy to condoms can also cause the problem. It the problem persists, it is time to have your doctor examine you.

Can be.: Yes, this can happen; probably nothing to worry about if transient and otherwise asymptomatic.