TTC #2 implantation bleeding

Hi! So we are trying for our second kiddo. Today my period was due and I tested this morning and got a very very extremely faint line. Tonight I had some bleeding, light pink, when i wiped and i am cramping. I am afraid it’s my period. I don’t want to test until tomorrow because I peed recently and my urine won’t be as concentrated. How long has everyone’s implantation bleeding lasted?!