Hello and welcome to Ask a doctor service. I have read through your question and here is my advise. It is possible that you are getting a false positive test since your blood work is negative for pregnancy and you have also got your periods. The most conclusive way to rule out pregnancy is to get an Ultrasound done. Since it is not advisable to take adderall during pregnancy you should consult this with your gynaecologist incase you are pregnant. I hope that answers your question. Let me know if I can assist you further. Wishing you good health.