Discharge at 19 weeks

I’ve had a lot of discharge throughout my pregnancy but I’ve been having discharge the last few days that just about soaks my panties. I’ll have to admit it does smell quite like pee but I don’t feel anything coming out. It’s just there when I pull down my panties. I’ve noticed its happening more now that it’s in the mid to upper 70s here so I’m sweating a lot more. I don’t think it’s amniotic fluid because I don’t feel a gush when I stand up. I just wonder if it’s normal. I have my 20 week anatomy scan next Monday and after reading so many stories I’m worried it’s something to do with my cervix or preterm labor. Has anyone else experienced this? Is it just normal pregnancy discharge or piddle pee from my bladder being weak?