Positive test after miscarriage??

Need help from fellow ladies who have experienced miscarriage! On 10/1 (at 8 weeks pregnant) we found out baby stopped growing and heard the dreaded word...miscarriage. I passed naturally and stop bleeding/spotting on 10/12. Hubby and i were ready to start trying again (haven’t gotten period again, yet). Started feeling weird the past 2 days so I took a test this morning and got a very faint positive?! Not trying to get my hopes up, but how long can you get a positive test after miscarriage?