How many days should i wait to take a hpt after the first day of my missed period.....?

No need to wait: If you have missed your period, there is no reason to wait; you can do the home pregnancy test now. Keep in mind that your most accurate test is done with the first urine of the morning.

See below: 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. A negative result from a test done too early does not exclude pregnancy.