am I loose? what?

Okay before you guys all inform me that the vagina is a muscle, believe me I know. But before my boyfriend and I had sex I could never really finger myself just because I couldn't gett my fingers in. Then him and I had sex for the first time and he came in about 15 minutes it was great, but now when I finger myself it feels "tight" for a second and then some moments it feels like a cave and it freaks me out because I don't want my boyfriend to suddenly think I'm "loose" and the second time we had sex he couldn't cum because he said he really had to shit and piss the whole time so he couldn't really focus ig, so after that I felt very self conscious and am confused.. why does it expand so much when I finger my self sometimes because I don't want my boyfriend to be doing stuff and feeling that. help?