"popping" cervix?? help please

WV
I'm a worry wart, I'm absolutely terrified of going into pre-term labor so I've been so scared the past two days. The past two days I have been experiencing a "popping" feeling where I assume my cervix is. It's very low, I'm like 90% positive it's my cervix, or the bottom of my uterus. I don't have another doctors appointment until May 11th, and I will be 26w, 3d, so I'm scared to sit back and wait but don't want to go in if it's normal. What do you ladies think it is?