What's your opinion on what this sounds like

Miss k ♡♡
So I did my workout just now. 15 mins elliptical, 15 treadmill. 10 squats, and knee to stomach touches, and fire hydrant. But as I was on treadmill it felt like something qas pulling underneath my stomach, going down by my vaginal area but felt like inside ! Best way to explain. Is that my body telling me to slow down? I am 33 weeks pregnant! :)