What are the chances?

Ok, so I think I might be pregnant. I've been feeling off for at least a week and a half. Aunt Flo is now 2 days late, and usually she is rather punctual. Although, my husband and I only had unprotected sex once this month, because it was supposed to be a "not fertile" day (8-9 days after Aunt Flo's last arrival). And I took a CB test this morning (not first thing though) and it was negative. But I'm still not sure. Should I try a different brand? Because I heard CB has a higher rate of false negatives. If so, which one should I try?

On top of that, if I take another test, and I am prego. What do I tell my husband? We were trying not to get pregnant, because we have an 8 month old, and financially, things could be better. And my husband is pretty miserly. So if I tell him another baby is on the way without our monetary ducks in a row, he's going to shit a brick.

Suggestions?