Hi there, The nausea and the diarrhea you are experiencing must be due to the metformin. Metformin is known to cause side effects especially in the initial few days of use. Metformin is usually given in women with PCOS problems, if you are having the same then you will require ovulation induction by Clomiphene and/or injectible HMG to get pregnant. But first you need to be completely evaluated for any other problems of infertility, your hormone levels, tubal function need to be checked, so also your partners semen analysis as well. Your overall health including any previous illness, diabetes, thyroid problems need to be ruled out. I would also advise you to take Folic acid if not already started. Hope this helps. Regards.