BFP after IUI

My wife and I had our first unmedicated

IUI

this month and to our surprise it worked first time! I had some symptoms like being tired, hungry, thirsty & hot. I got a my first positive on 9dpiui and have been testing ever since. Am now 12dpiui

I am really worried it won’t stick! Nothing has given me a reason to worry, besides feeling pretty ok now, and I don’t have sore boobs which seems like a common symptom. The only things I’m experiencing now feels like AF is on her way- cramping, tired.

I have experienced light discharge (milky white) and google says it’s normal for early pregnancy OR could be a sign of MC.

Can anyone offer me some reassurance? Because we went through a private clinic, we have a HCG test on Monday and an early scan at 6 weeks