Had done iui on 4th july it's now day 12 and i done a hpt it came out negative. suppose to do bloodtest on the 19th july was it to early to test?

Patience...: Patience is a virtue that all parents should seek. From the 4th to the 19th is a very short time (to relax and not think about babies). A urine pregnancy test done correctly should give a reliable result after 2-3 weeks (making it less likely to be a false negative if it is negative). Hopefully, the blood test will be a positive, but there should be no need to give it another thought until then.