Had unprotected sex on aug9 and period came aug31 and sep29 bhcg 15 sept level less than 1.2 miu/ml bhcg oct.6 level 0.1 miu/ml i am pregnat ?

No: A normal pregnancy did not begin on august 9th. With that bhcg value it is unlikely that fertilization occurred before september.

Unlikely: 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.