I have no idea what to do help please!

So I feel like I MIGHT have a bladder infection. I'm not sure if it's normal pregnancy feelings or not. My stomach kind of hurts, especially when I have to pee, I'm nauseated at times, I have to pee a lot and it's not always a lot of pee. Could easily be from growing uterus but I had a uti a few weeks back and I'm worried the antibiotics didn't work. I'm almost 21 weeks so I know the er would probably send me to L&D if I went in, right? Should I go into L&D or wait until my Apt on Tuesday?? Will they do anything or tell me to wait until I can see my regular doctor???