Diarrhea almost every morning, loss of appetite, more veins, peri is late (irregular so idk) & lump in left pelvis but 2 neg hpt. possibly pregnant?

Questionable.: Your symptoms don't specifically represent pregnancy but are still concerning. I would want you to see your primary care physician ASAP.

Unlikely: With 2 negative HPT and irregular periods you are not likely pregnant. See your doctor if your symptoms continue another few weeks.

Yes: If your period is late do a pregnancy test. The diarrhea, loss of appetite and veins are very non-specific, but all fertile women are pregnant until proven otherwise.