First time Clomid user!

I have 2 kids beautiful girls which I was able to conceive naturally. My youngest is 6 now. I was diagnosed with PCOS 2 years ago and due to EXTREMELY irregular periods and no ovulation we have not been able to conceive the 3rd baby. Well I was prescribed Clomid 50mg my doctor originally said take days 5-9 but I called today since AF finally showed after taking aygestin and now she wants me to take Clomid days 1-5 instead, has anyone taken it days 1-5? If so, was it effective? My periods normally don’t last longer than 3-4 anyways so maybe it’s a good thing I’m starting earlier but you don’t really hear days 1-5 so I just wanna know if anyone has done that. TIA 🙂