Toddler urinating too much

Okay so I’m waiting for Monday to make a ped appointment but i just want opinions and if any other mommy out there experienced this

I’ve been noticing that my 3 year old has been urinating quite often. He goes to pee and literally every 3-5 min he has to pee again. I’ve also noticed that when he does pee not much comes out certain times, also he cried out of frustration because nothing comes out at times. My sister in law says a uti but there’s no pain/ burning while he urinates at all i also make sure nothing is around his private area as in lint or tissue. Any help mommies will be great 🤦🏻‍♀️🤦🏻‍♀️🤦🏻‍♀️