Does withdrawal bleeding after duphaston means no pregnancy? i got heavy bleeding for 2 days and light/spotting bleeding for 3 days?

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.

With that amount of bleeding you either have a period or if conception had happened you just had the miscarriage but I doubt. A negative urine pregnancy test with an early morning sample as soon as possible can erase your doubt.