Advice!

Okay so this would be my 3rd if it were to happen but for some reason I am so worrued and I apparently forgot about the signs of pregnancy! I am 5 months post partum and I have only had one period! Long story short apparently since my last period I am 29 days late and i just had a little bit of blood but that was this morning and ive got mild cramping! I went ahead and took a test because there could be a possibility and it said negative but I'm just wondering if I should wait a few days and then retest or if i shouldnt be to worried about it?