I started what I thought was my period 4 days ago.. but it is just brown and very light like a quarter size all day, no red at all I know you can have old blood but I don't know if that's what it is because its been going on for 4 days or if this could be me pregnant. Me and my husband are not trying but don't use protection we just follow the rule when it happens it happens so we aren't against another kid but were not fully trying.