Hi, Welcome to Healthcare Magic Forum,
It is not necessary that bleeding should happen, every time you have sex for pregnancy to happen. You have not mentioned if your periods are regular. If your periods are irregular you should get yourself examined by a Gynecologist to rule out Hypothyroidism
and PCOS. A Ultrasound
scan and Blood test
will confirm it. You may also need to get your husband's semen analysis
done. If your periods are regular, have sex regularly every alternate day from 10th to 20th day of your cycle. All the Best. Take Care.