I got my mirena taken out feb 19 started taking bc pill a week before that then i only took it a week after then stopped its been 3 weeks since i stopped been having pregnancy symptoms for about a week now negative test could i be pregnant?

See below: 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.