Wa'alaikum assalam! Aih, itu memang common during pregnancy, resting heart rate kita naik naturally sebab blood volume bertambah dan the heart works harder to pump for two, so don't worry sangat lah. A few of my mum friends mentioned the same thing around second trimester, but definitely mention it to your doctor at your next check-up just to be safe, especially if you're feeling dizzy, shortness of breath, or kalau your heart is racing even when you're resting, they'll probably just reassure you it's normal or monitor it, tapi better to let them know just in case!