Tissue or something in toilet after peeing?

Hello everyone I am 5 weeks pregnant as of today, and probably for about a week now I've occasionally noticed "stuff" in the toilet after peeing. Not every pee, but maybe once a day. The stuff is typically small, clear/white, floats, and almost reminds me of an oatmeal flake. Its definitely not CM, and I haven't had any bleeding or spotting. I see the doc Thursday for my first apt and plan to ask then, but it's my first pregnancy and my body is doing weird stuff and I don't know what has normal and what's not. Any insight is appreciated!! 
Also, I have no idea what hole the mystery stuff is coming from.