Glow saying I'm further along that possible...?

Ashley • •Almost 24 Years Old•YT Vlogger•Married•3 Year Old Daughter•Currently Pregnant!•
Glow is saying I am 5 weeks and 4 days along but that can't even be possible because we weren't trying 5 weeks ago! According to when we started trying and started having sex I would only be about 3 weeks pregnant right now. So why is Glow saying I'm 5 weeks and is there a way to change it?