Palpitations

Hello momshies, ask ko lang po I'm on my 33weeks and have been experiencing contractions. My ob needed to do an IE para makita if open na cervix ko and she told me closed pa dw pero manipis na. Pina take ako ng Isoxilan (uterine relaxant) pero may side effect: mild palpitation. Okay lang ba mgtake nito kahit may palpitation na ako before I took this med. Hindi ba sasama yung palpitations ko dito? Will appreciate your replies. ☺