confused. ttc

So, my last period was March 6th. My periods were pretty irregular, but recently have been pretty regular the past 4 ish months. Right after my period my husband and I decided to have another baby. around the 26th of March we started having unprotected sex, and we have every day since (I've been off birth control for almost 6 months already). but I think we just barely missed my fertile window but since my cycle is kinda whacked I'm not sure. It's now April 8th and I still haven't gotten my period. I took a pregnancy test 2 days ago and it was negative but I've been super nauseous and my boobs have been sore. When should I take a pregnancy test?! No signs that my period is coming and I'm freaking out excited..