After how many days of l bleeding you should take home pregnancy test?

period are irregular,,,,3time period come bt the timing was irregular first 2 time it was early and now it is late......but bleeding is heavy like normal period and lasts 4days as usual...... after 12days of last period took the urin test was -ve. waited another week and retest also came -ve. so 3 weeks after the last period (that was the 8th week after we were close) urin test was -ve. is there any risk of pregnancy?