What’s the earliest a pregnancy can be detected? How long is the process of implantation.

Me and my boyfriend had sex for the first time on the 19th of April. A day after my period ended. We didn’t use a condom but he pulled out. About two days ago, at the peak of my fertile window we had sex and he didn’t pull out. I have a cat that’s usually pretty calm and distant but when I got home today she was abnormally affectionate and wouldn’t leave my presence. So I looked up why and to my surprise many answers to this question was pregnancy. I know the internet isn’t always correct or it could be an old wives tale but is it possible for me to be pregnant this quickly? Or rather for it to be detectable?