I had my period for about a week, although it was extremely light, (almost like spotting).
It finished on a Friday and I had protected sex with my boyfriend on Saturday.
The next night, I needed to go to the toilet every 10 minutes or so and only little bits came out. And on the Monday whenever I wiped there was the slightest, lightest bit of blood there and still is now.
I'm not too sure what it might be?
If anyone could answer I would really appreciate it!!

It would be too early for pregnancy symptoms. You will have to wait to see if you get your next period as expected. If not, wait 2 weeks and then test using first morning urine.

Thanks a lot, I'm just confused whether I would be pregnant seeing as he used protection though?

Anytime there is penile insertion there is a risk of pregnancy. There is no form of birth control that is 100% effective.