Ttc. lmp 9/29/16. cycle 30 days. idk when i ovulated, but been having cramps and lower back pain and pain on side of breast. when should i take test?

When period is late: A urine pregnancy test, done correctly, gives a reliable result 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and thus lead to a repeat test. If a woman gets her normal regular period, then she is not pregnant, and a test is not needed.