###Human: I got my periods a day after a positive pregnancy test. What just happened? ###Assistant: Hello. The faint line could be because of hormonal changes due to the hCG injection you have taken. The test is to detect hCG levels in your body, which can be detected during pregnancy. However, if you have a doubt then get back to me. Take care. For more information consult an obstetrician and gynaecologist online -->