Had unprotected sex on the 8th, ovulation test positive on the10th, one brown spotting yesterday evening and one this morning. could i be pregnant?

Yes: The timing is certainly reasonable and you certainly could be pregnant. You would not likely have a positive test for at least six days or so after your ovulation and in many cases with over-the-counter testing it would not be determined until your missed period. The spotting could represent estrogen changes from ovulation for implantation of a pregnancy.