Forgot the Progestrone!!!!

I always had a ultrasound and bloodwork one week after my IUI and always took progestrone from the day of the IUI until the day of the beta - but with this new office there was no ultrasound or bloodwork one week after IUI and I was never told to take progestrone nor was a given a scrpit for it - now I am 10 dpiui and wondering if I should be taking progestrone - yes I know I am very late on this - I wonder if it makes a differance or if it is a problem that I have no been taking it - I am calling them in a few minutes to see what they say. I have some left over from my last IUI that I could start taking - but I wonder if it is already too late for that.