My period is due in 1 day (tomorrow), no period pains and all pregnancy symptoms. negative pregnancy test 3 days ago, was it too early to test?

Depends: Normally want to test no sooner than 2 weeks after unprotected sex. If negative, repeat in 1 week. Best to use first morning urine for test as hormone levels are highest in that sample of urine. At 19 y/o not uncommon to have some irregularity in your periods. Hope this helps. Best of luck. Dr R

Too early to test: Conception, as defined by the generation of a fertilized ovum, occurs within day or so of the sex. However, it takes about two weeks for the embryo to make enough HCG to produce 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. Use first morning urine and follow instructions for the test carefully.