Bad lower tummy pains.cycle is 25days, started 10/4-10/8. sex10/9, planb 10/11.neg test 10/22. started pains in lower abdomen(don't feel like cramps,just intense pain and only when i lay on my back every 5 mins or so)am i pregnant? still no period?

Conception occurs within day or so of the sex. It takes about 3 weeks for the embryo to make enough HCG for a positive pregnancy test. Blood test may be done a day after a missed period. Home pregnancy tests should be done 4-5 days after the missed period. If the result is negative repeat the test in 4-5 days. Use first morning urine and follow instructions for the test carefully.

Symptoms as described can represent pregnancy outside the uterus (ectopic), so see your GYN physician as soon as possible for an exam and a serum HCG test or ultrasound. Ectopic pregnancies need immediate attention.