10 weeks pregnant and just slight bleeding?

I'm just over 10 weeks pregnant today and when I went to the toilet earlier there was just the tiniest smear of blood when I wiped. It was red, not brown or pink, but it was literally the tiniest amount on the toilet tissue. It was only there the first time I wiped. It hasn't happened since and I'm not bleeding or spotting at all. I've had no cramping aside from the odd twinge in my sides, but nothing painful or even uncomfortable. Sorry for the tmi, I just wondered if it's something to be concerned about. There's been nothing since and it was about 10 hours ago, and all the pregnancy symptoms are as strong as ever.