My last period was 05/08/ i spotted light pink spot on the 29/08/ then nothing until the 12/09 spotted brown on and off even now, hpt neg?

Repeat: Home pregnancy tests become positive at about the time you'd be 1 week late. I'd repeat it again in one week. If it's negative, see your doctor.

Blood test for HCG: 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.