Chances of becoming pregnant whilst breastfeeding?

[ohcluttergotme]

Got a 6 months old baby and haven't had any periods.

Had sex for first time with my DH last Monday and on Tuesday had sticky white egg mucus which means I think I ovulated.
So, feel I'm kind of in the 2WW.

What do people think are the chances of conceiving?

If negative I'm going to see the GP and request the contraception injection.

I got pregnant while bfing but my periods had returned.

Unless the baby is exclusively breastfed with no bottles/dummies and no big gaps without feeds (e.g.. overnight) then breastfeeding won't offer much protection.

She was exclusively breastfed and feeding a lot through the night but a couple of weeks ago I started to gently wean and also offered a bottle of formula every other day.
I'm wondering if this has been what's started things off?