I Took Periods Postponed Tablet Last Month And I Got

I took periods postponed tablet last month and I got my period on last month of 11 ,we r planning to convince so we did sex on my fertility days 3to4 time s a day and today that is 13 as i missed my period for 2days i just took a home test but the results was negative , what can I do to get pregnant , r should i take test after some time