No hope??

I’m a week late with no signs of my period (ie no cramping, cravings, normal stuff for me). Well today husband and I had great sex and when done I went to the bathroom to find a little strip (I don’t know what to call it) of blood on the tp. Is it possible that it’s implant blood or am I starting my period? I’m usually heavy when I first start so it’s not normal for me to just have spotting. I’m also very on time with knowing when my period is so this is something very weird. However, I have started a new job and just moved so my husband has been saying maybe it’s just stress.