loose vagina after periods

hey i wanna know that is it true ...after the one or two days of periods the vagina is loose nd after 4-5 days it becomes tight again..i had sex wid my gf just after one day when her periods finishes nd i feel her vagina was loose...and then she was saying it..and she had never tried fingering ever before nd we had sex for the 5 times and before that she was virgin ,,means she was saying that i was her first guy but she didn't bleed ever but the first time the vagina was tight nd she felt pain nd m 18 nd she's 16 any suggestions would be appreciable..thnx