Advice?

Why else would a lump come into my stomach? Like I been having pregnancy symptoms ( nausea but no vomiting, headaches, dizziness, heavy stomach, back pain, pins and needles thru body, tender boobs) but I haven’t missed a period. So I don’t no if I am pregnant because after a faint positive I had a heavy bleeding and when I took it again like a week later it was negatives… I had another period since than I haven’t checked in with the doctor cause idk if it’s needed… but why would I still feel pregnant my body’s been feeling weird since last month..