Dizzy, low bp, headache, breast tenderness, late period (1 day), always hungry, always sleepy, lower abdominal cramps, regular cycle, am I pregnant?

Possible... If you are sexually active and your period is late, then pregnancy is possible. You should take a pregnancy test now to evaluate this further. If the test is negative, then repeat it later this week if you still don't get your period. For additional information, please visit my personal page @ www.Obgynhelp.Com.
Dizzy and low BP. Go to an er and have some blood count checked. Your symptoms of dizziness and your low BP could indicate some form of anemia. In the er, they can also check your urine to see if you are pregnant. Your symptoms sound serious and you should get examined and have some blood taken to arrive at a diagnosis and a treatment plan. Good luck.
Pregnant? Your symptoms are consistent but not diagnostic of pregnancy. Do a home pregnancy test if you do miss a period. These tests are highly accurate when taken 12 days after conception.