Hi, thanks for using healthcare magic
It is possible that the ring worm
(caused by a fungus) has been secondarily infected by a bacteria. The description of 'bumps with pus' sounds like a bacterial infection.
You should consider visiting your doctor before taking any medication.
He or she may suggest a topical antifungal
cream which may be combined with a mild steroid to reduce the itching.
If he or she believes that there is evidence of a bacterial infection topical antibiotics or oral antibiotics
that are considered safe in pregnancy
may be used.
I hope this helps