Spotting or period?

So me and my s/o had some fun (lol) sometime around last week and we did use protection but I'm still not 100% sure about its efficiency. (Not pills)

Yesterday my period was supposed to come. And as my period is usually heavy and with a lot of blood pouring out, now it came so much lighter than usual. And the blood was also a little lighter colored. As my period usually came out of my tampons almost each time and staining my panties somehow, now it takes a lot to fill the pad.

I got the usual period backpains and tummy pains however. But I'm just not sure. This is my first period before losing virginity. Could it be because of that? Or is this the spotting that could signal pregnancy? I'm on my second day of it now and still light