When to start using bed mats to protect mattress from waters?

[Jellybabie3]

So im a while off (19+4) but wondered when people start using bed mats to protect their mattress from waters breaking.

Thank you oopsy. Our scan is on Monday and my OH is poised with paintbrushes to start on the nursery! Were thinking ahead because we are so damn excited 😁 been doing alot to the house to make it baby friendly but that mattress is MINE....(yes i know it will get puked on and wee'd on but i will defend it as long as i can....)

I had my waters break in bed in the middle of the night as the first sign of labour. Jumped out of bed, not a drop in the bed.

Mine broke in bed but not much got on the bed, I stood up and that's when most came out. This was at 35+5 So I'd do it before then 🙈

My waters didn't break on any of mine (3)
They were all broken in hospital

6 dc and with 3 my waters had to be broken.
With dc4 the baby was born in his bag.
Dc5 & 6 they went as i was delivering baby.

Get a decent waterproof mattress cover anyway, useful for when bf in bed or when a toddler is in your bed in case of accidents or whatever. We have one from ? John Lewis? which isn't rustly or anything. I'd still prefer one like we have on all the single beds in the house which is cotton both sides with a waterproof layer hidden in the middle but they don't make them big enough :(
Have just bought a cheap mattress cover off eBay (impending home birth to protect the sofa bed) and it is the plastickiest thing ever, so read reviews before you buy one!