Possibly pregnant

Im 18 days late , ive only ever been late once before . When i got pregnant with my 15 month old .

I am 18 days late , I have taken many pregnancy tests and all came negative . I think I see a faint line but when I showed my cousin she said nothing was there.

Now today , i use the bathroom and theres light pink blood on my panty liner . My period has always been dark red and never like this.

Could I be pregnant?

My body is changing like it did with my son , but the light pink blood and negative tests make me question it .

Any advice ladies?