Possible Mucus plug???

I was walking in target and had to stop due to some strong lower back and hip pain and this pressure of having to pee or something right above my vagina area. As I slowly made it to the restroom the pressure of having to pee eased up but when I wiped I had a very mucus like discharge with a tint of yellow 🥴 I still have the string hip and back pain though! has anyone else experienced this?? I see my ob tomorrow so I do plan on telling her. Any advice is appreciated, this is my first baby 😅