Ay normal lang yan, mama! A few of us felt the same around 30 weeks, usually a few times a day or every few days is okay, pero if you're getting them super frequently (like every few minutes for hours) or if may pain na talaga, mas better to check with your OB just to be safe. The fact na mawawala pag nag shift ka ng position at hindi masakit is a good sign, pero since braxton hicks can sometimes be hard to distinguish from other things, better peace of mind lang if matanong mo ang doctor mo, especially since you're tracking it nightly. For now, try sleeping on your left side, use a pregnancy pillow to cushion, at stay hydrated kasi dehydration can trigger more contractions. You're doing great, mama!