Pregnant or Something Serious?

Patient: I’ve been having slight cramping in my lower abdomen and back, waking up once or twice a week with nausea, not much of an appetite, spontaneous headaches,a few times my mouth has had this metallic taste, my breast are a little tender not much but a little more tender than usual, I’ve been seeing light bleeding only when I wipe. My period is very irregular but I’ve already had it for this month and a week after I had my period is when the light bleeding began and I also had insomnia four nights in a row. I’ve taken 3 pregnancy test and they all came out negative. I would like to know if there are any other diagnoses that match these symptoms.

Symptoms: Lower Abdominal cramps, lower back cramps, metallic taste, insomnia, no appetite, Nausea, headaches, tender breast, light bleeding