3rd sweep in 6 days

Poppy

I've had my 3rd sweep today at 40 weeks. The midwife said she could feel where they had been last time and managed to get another 1cm in, she said my cervix still needs to be softer and my bishops score is 4 she also said she had detached the last bit of membrane. Baby is engaged and she also said there is no show/plug left and because I'd laid so still she'd been able to give it a double sweep. Then she said sweeps before 40 weeks aren't known to be all that successful. I am really struggling to process this information, what does she mean she got another 1cm higher? I thought a sweep was a sweep I didn't realise it was done in levels lol. Does anybody have any idea what this means?