I'm 2weeks pregnant but i'm on periods bleeding red blood and there is tissue a medium one and i have pains at the lower part of my stomach could i be having a miscarriage?

You could be having a miscarriage. You should see your doctor for HCG level test and repeating the test in a couple of days. HCG levels usually double in two days in a viable pregnancy in the uterus. Wish you good health!

Your symptoms are indeed consistent with a possible miscarriage, but with a positive pregnancy test, and bleeding, pregnancy is also possible outside the uterus (ectopic). See your OB/GYN physician for an exam and other testing.