12 dpo, tested 1x got a very faint line held up to light. 2nd test 2 days later no line. cramping, bloated, tired/sleepy, low back pain. am i preg?

Sorry : Probably not. You could test again tomorrow , or wait a couple if days to see if period starts. Best of luck!

Probably not: With a negative pregnancy test, it is unlikely that you are pregnant. Having had a positive test does mean you had conceived but with the subsequent negative test, the pregnancy has failed and you should expect to have you period soon.