My period is due in 8 days. i did a clear blue ovulation tracker that showed i was not ovulating. if i took a plan b would it work to prevent implantation? cycle is regular 28 days?

EC is only expected to work if it is taken within the time frame listed, for most 72 hours from exposure.

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.