Implantation bleed or not

Hi 

Iv got a 10 yr old 7 yr old and a 14 week old my baby took over 6 years to conceive so I was extremely blessed

I didn't think I'd catch again but today I got a pinkish discharge like when I caught last time it's 4 days away from my period been looking on alot of forums and it says it cud be implantation bleed am i that lucky or am I wishful thinkin another baby would be a miracle