I have bi proxima tubal obstruction is it becoz of my previous cesaren sec im unable to conceive now i knew this after 4 years of c sec so is it late?

Likely, no: While possible that your tubal blockage is due to scar tissue from your cesarean, this is less likely. Endometriosis or a pelvic infection are most common reasons for tubal blockage. At 31 years of age definitely not too late. Hang in there, see a reproductive endocrine and infertility specialist. Many ways to get pregnant these days!