Need help and advice

How often do you have sex to increase chances of pregnancy... in our case it is about 3-4 times around the time of ovulation and then nothing for the rest of the month... do you think that is enough?

We have been ttc for a really long time, tried iui 3 times, not successful, not yet thinking of ivf...

The whole process is taking a toll on our relationship and we r never together just for the enjoyment... it is only because we want to get pregnant... i'm getting negative to the idea by itself now...

Anyone sharing my situation? Need advice... :(