I Was Sexually Active When I Got An LH Surge,

I was sexually active when I got an LH surge, but getting this does not mean I ovulate and after seeing a fertility doctor after my sexually activity, he told me I am not ovulating. I was given metformin 500mg which I have been taking day six days now. My period should be due soon. I read that metformin can delay periods, if I miss mine this month what should I do?