Suggest Remedy For Insect Bite On The Forearm

I am 36yrs old, 5'6", 152lbs, 21 weeks pregnant. I was stung by a wasp on the forearm yesterday morning. I put OTC cortisone ointment on the area last night & this AM, but see no improvement in indurated area, maybe some lateral spreading of erythematous area. There is a 4mm bulla at the sting site. Can I use 0.1% triamcinolone cream that was prescribed for pregnancy-related eczema?