BFP to a BFN??

I’m currently 10 DPO and this morning about 7am I took a first response pregnancy test and it came back with a majorly faint positive. Well later on about 3 pm I took another and it came back completely negative. Do you think I’m out or was it just because diluted urine in the evening? I have light dull cramping, super sore boobs, and crazy dreams every night.