Could i be pregnant? is this normal?

I lost my virginity at the beginning of this month (to my boyfriend, who i love very much). We had safe , of course... condom with spermicidal lubricant, and the condom did not break or anything. But i started my period today (on time) and it is WAY lighter than normal... i'm a little concerned. is this normal after losing your virginity? i took two tests (digital) and both had ERROR on them... i haven't gotten to get another yet. Please help?!