Feeling "off"

I don't know how to describe it but I've felt off all day. Only 3 dpo but I just have a feeling... with my oldest, I got pregnant a month after stopping bc. With my miscairrage, I got pregnant 2 months after stopping bc. Then to have my rainbow baby, we were ttc for 10 months after our loss. Been off bc since October. Not really trying but not preventing. I know it's too early to have any kind of symptoms but I just feel like it may be it already... anyone else just "know" super early if they were or not? I would not be disappointed if I'm not pregnant but I just have this feeling... I'm probably just crazy...