Oh, sorry, it would have to be between about the 18th and the 28th. Don't know where I got that 9th.
If we ignore what the doctor said and just use the first day of your last period on a conception calculator, your possible window of conception would be after your period in May, probably somewhere between the 9th and the 28th.
Are you saying you also had sex in May with the guy from April? (Was it after your last period; i.e., the one in May?) When the doctor gave you the due dates, were they based on ultrasounds, and if so, how far along were you at the time? (Using a conception calendar will only be helpful if your due date is reliable, so it matters how the doctor got to the due date.)
Like around wen? Do u have the pregnanxy calendar thingy?
The baby is not from the man in April. You would have conceived in mid- to late May.