Learned I was having contractions while doing fetal monitoring...

I can’t feel them at all, but the screen showed I was having them every 7-8 minutes or so while I was doing my non-stress test for baby. I assume this is just Braxton Hicks or something? Anyone else been told they were contracting without feeling anything? Makes me nervous, but I am sure when they’re active labor contractions they will be much stronger and closer.. and I will feel them lol. I’m 33 weeks & 3 days, they mentioned checking my cervix but ended up not checking me yet.