Am I pregnant?

Hey guys, I a officially 4 days late for my period. My husband and I aren't TTC but we would be elated to find out that we were expecting. Either the day of or before my ovulation we used the pull out method. I pretty sure he waited a little longer than he needed to. I took a pregnancy test on the day after my missed period and it was a negative but I've been nauseous, had back aches, and today I had some light spotting. I'm reaching out to see if any of you had similar experiences and still ended up pregnant and I also wanted to know how often false negatives are? Thanks!