15 dpo faint line

Has anyone ever had such faint line on 15 dpo and gone on to have a normal pregnancy? This would be my 6th pregnancy with a chemical and missed miscarriage and 3 live births. With all my other pregnancies I had positives at 9/10 dpo. This month I spotted 10/11 dpo and just assumed it was my period as I usually spot before my period. But I never got it and took a test and got this.