Clomid for 3 days?? Please help!

My doctor just ordered my 4th round of clomid when (if) I get my period in January. The first round I did 50mg for 5 days. 2nd and 3rd round I did 100mg for 5 days. Pretty typical from what I’ve read online and on the message boards. This round my doctor wants me to take 150mg but only for 3 days. Cycle days 3,4,5. Has anyone ever done this or heard of this? I’ve only read about a 5 day treatment cycle. Any info would be much appreciated. I want this baby so bad!! Thanks!!