Hello, I'm a 21 year old female and recently I've noticed that sometimes I need to strain when I'm urinating. Most of the time I can pee normally and basically without any effort, and other times it feels like I physically have to make the effort to pee and to get all the pee out and at times it feels like it's not completely out. It doesn't hurt to pee and I have no itching etc. Is this normal since it doesn't happen all the time, or should I be worried/keep an eye on it?