My wife did not get discharge during sex, even she didn't feel excited during sex. any suggestions ??? & is it necessary for my wife to get discharge for pregnancy ???

Many women do not have much increased vaginal fluid when sexually aroused. Neither arousal nor discharge are necessary for successful conception and pregnancy. However, if you have been having regular vaginal intercourse for more than a year (including sex midway through her menstrual cycle) without conception, both you and she should be evaluated for possible infertility. Good luck.