What to do..?

Hey guys! So I'm kinda in a bind..my fiencé and I are TTC (both women and bi) the way we've done it is we had a Three some because we both wanted to explore our sexuality. He came in me, and since then ive been feeling off. Like, I'm really bloated, have cramping in my lower left abdomen and have been very nauseated. Ive read so many things that say some people can tell theyre pregnant right away, within a few days. Is this true? I just am not sure what to believe on the internet haha thank you everyone!