Testing negative then positive after?

An

Has anyone tested negative like 10dpo then positive the day after or something? Need some hopeful stories... trying not to symptom spot but I started cramping on my lower right side earlier very lightly like a pulling twitch I’ve tested with FRER but pure negatives... Aside from that I just have light headaches... thats probably just because I’m tired lol I know maybe I’m just testing too early?

TIA