Yes but I'm not going by the date of my period as I only had sex with him once and that was afterwards by nearly 2 weeks so that makes me nearer 4 weeks than 6. I'm sure you'll agree it's not possible to be pregnant unless you have ML.
In my last pregnancy my official due date going by my period date was 12th December, but at the early scan they realised I hadn't concieved until after that date and they re-estimated my due date as Boxing Day.
