Need to go to doctor or no

So every month for a few days before my period starts I get this thick white discharge for a few days and then it usually goes away. I have had a yeast infection before but a long time ago so I don’t remember it that much but I feel like it was way more uncomfortable itchy and cottage cheese looking which this is not. This is more like a bunch of thick cloudy discharge that is on my underwear. It doesn’t have a super unpleasant smell at all but almost smells like ammonia?? Do I need to go to the doctor or is this normal when you are about to start your period? I also just went in a few weeks ago for my annual and they said everything was good so I don’t believe it would be an STI.