Is it true that if the man is on top with your legs on his shoulders, you can get a UTI easier?

My husband likes being on top and putting both my legs on his shoulders and I end up with an annoying UTI.  Is this position the cause of an UTI?

I am suffering with an UTI right now, my bladder is soo sore.  My Dr. put me on Macrobid and told me to take one after intercourse, I did this and still got a UTI.

I feel afraid of having sex :-(