Feels like baby is shaking

Hey everyone!

I've noticed for a few weeks now that sometimes it feels like the baby is shaking/trembling. I haven't thought much of it because it so rarely happened, but these past two days it has become more frequent (several times a day) and is slightly painful. I don't remember this happening with my first so I wanted to see if anyone else has experienced this? I read online on another forum that it could be the baby stretching, but who knows for sure 🤷‍♀️ I plan to call the doctor later today when they open, but wanted to check on here too.