Well if its more than a year since you are trying for a conception, you need to be evaluated.You can have a planned intercourse between day 8 to day 18 of your cycles , followed by progesterone
support in the second half, for another 3 months.If you still don't conceive,then please go for a HSG
,to see if tubes are fine.Though your partner has a son, still there is no harm to do his semen analysis
now.keep me updated ,
i think, I have answered you.