My dear, four months seams like a lifetime when trying hard, but in reality infertility isn't something to cross ones mind until after 12 months of unprotected sex. Unless there is a reason that you feel that you are having troubles? Like tubal issues, infection, std, age? Even male infertiltiy.
For us we knew ahead of the game that we would have some problems considering dh (husband) had zero count due to a slip of the knife.
Take it easy and don't push the sex every day. Give it at least 36 hours to recoop the count. No lubes as it can kill the sperm including spit.
Cramps ahead of flo is normal for some, as is bad pms health forum mode, thats me.