Can a pregnancy test be accurate after 2 days after intercourse 2 days into ovulation?

If intercourse and ovulation timing matched, 7 days after conception. Too soon, otherwise. Implantation of the fertilized egg must occur before test will show up.

No. 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.