concerned

Brianna
I'm currently 9 weeks pregnant with my rainbow, but I have an important question that pertains to right before women miscarried. 
I feel like something's not right, and I'm wondering if anyone felt like a "heavy" feeling in their uterine area right before they miscarried. 
I had a miscarriage last February, and I don't remember this feeling, but mine was a missed miscarriage and my body didn't begin the miscarrying process for 3 weeks after my baby died. I typically get the "heavy" feeling right after I stand up from sitting down  while (like something is quickly sinking inside my body), or if I'm walking at a slight incline. Another way to describe it is picture a watermelon in a plastic grocery sack- I feel like my uterus is the watermelon, and it's just hanging there. 
I should add, along with this sensation, I have lots of air coming out of my vagina. Air bubbles form and come out all day long (I know what a queef is and it's not that). 
Strange question, I know, but I don't have my next appointment for 2 weeks, and my insurance won't cover an ultrasound right now, and it's too big of a financial burden to get one and pay out of pocket for it. I just need some peace of mind because I feel like I'm gonna lose this one again. 
Thanks ladies.