Faint line on test

[Mayia19]

Hello was wondering if anyone can help me I had a missed miscarriage with twins ☹️ One was at 7 weeks and the other 7 weeks and 4 days only found out at 12 weeks when I should of been 13 weeks! I had surgery to remove the pregnancy nearly 3 weeks ago and did a test and saw a very faint line then did a test the next day and it was a bit clearer ! Not sure if it’s just hormones still left in my body or what sad any advice would be amazing

I was told by Epu that a pregnancy test should be negative by 4 weeks after miscarriage at the latest she did say that if after 2 weeks it was still showing a strong positive then to call in and get another scan so they can check me over.