Hello,
Welcome to ehealthforum and thanks for writing
For the conception to occur you should have regular intercourse during ovulation days which are usually 9 to 16 days in a regular 28 to 30 day cycle.You can also consider buying an ovulation predictor kit for that purpose.
It is difficult to comment regarding pregnancy right now as it would be too early.Cramps can be due to various possibilities.Right now just wait and relax and if the periods are missed then get a Urine test done after a week for pregnancy determination.Kindly visit a Gynaecologist for evaluation.
Take care!