Hard to pee??

M

So this is the second time I have got up while sleeping to pee. My bladder is very full but when I go it takes a little effort. I have to use my muscles to push it out and it comes out slower than expected. Alot does come out definitely a full bladder. The strange thing is the next time I had to pee everything was completely normal. No burning no itching no pain nothing like that. I have an appointment on Thursday so I will ask about it then. Could it be the postion of the baby when I'm sleeping? I'm 16 weeks. Its just weird its only happened in the middle of the night and was completely normal afterwards. The first time it happened was like 2 weeks ago.