Clomid results

I went to see my doctor yesterday for my 21 day blood result my first month on clomid and the results where I didn't ovulate on 50mg I finished my period 7 weeks today and still no period and I'm not pregnant she wants me to use 50mg clomid for next cycle and if that doesn't work she wants me too upp it 100mg 3rd cycle but I want to do a 100mg 2nd cycle because I know 50mg will not work has any one got any advice please