twins???

I got a positive pregnancy test Friday. Today I'm having very light pink spotting. I read online that it could be implantation bleeding, I read that it could be a sign if twins, is that true? Fraternal twins run in the family.

I thought that once you got a positive test that that indicated implantation was successful hence why I didnt think implantation bleeding could occur POST positive pregnancy test, hence why I mentioned the twins....