We've been TTC since February of this year, for our first. I'm 15 DPO and 2 days late on my period. I had a left side cramps from Monday - Thursday and today I have cramps all over. Crazy lower back aches were also a part of my symptoms. This morning I took a First Response test that said to take it the first day after your missed period. It came back negative, but I have read misellanious preferences in regards to the different pregnancy tests out there. Suggestions please?