Pregnancy while getting IUD

So, I have been feeling really off. (I know it may be just normal with hormones, this is my first baby) I am 9 weeks PP and my period is due on the 3rd. My IUD will be at my doctors office on Thursday. So I can get it in on Friday or Monday. (Whenever they have an appointment) well, IF I’m pregnant will they be able to tell with my urine. It would make me less than 4 weeks and I know their tests aren’t very sensitive. I took a test yesterday and it was negative but I know it’s so early.