Sounds like you conceived around the 11th of April. Don't worry. The guys in March don't count.
Thank you Annie, I dont know whats wrong with this countrys health system how they explain things etc. But today I went for another scan but an abdominal one and the doctor told me I was 7 weeks. I asked her if theres anyway I could have conceived in March and she told me theres no way of knowing? She didnt even look at my dates to calculate them and when I asked her which scan was more accurate she told me it was the first TV one. Then she told me I could be a week on either side whatever that means. Could you re confirm for me please?
You probably just got a too-busy doctor. The margin for error could be more or less a week IF you were talking about an ultrasound in your 12th week. In other words, embryos develop from one cell, and then split into two, then four, then eight, on a known schedule and at a known pace. But by the time they are a million-plus cells, some embryos have begun to develop slightly faster and some to develop slightly slower. Doctors will often tell someone who is interested in dating conception that there is a margin for error of +/- a certain number of days, depending on how many weeks along she is. But since your first ultrasound said you are in your 6th week, there is not a very big margin for error yet, maybe a day or two at most, possibly three days.
One thing that doctors don't always remember to do (and please don't go on to a doctor about how poor "this country's health system" is -- they are frustrated with it too) has to do with how they are trained. The medical way to define the weeks of pregnancy is to use gestational age, or GA. Doctors, nurses, ultrasound techs, medical textbooks -- anyone or anything medical -- are trained to begin the count of pregnancy on the first day of the woman's last period. That's when the GA of the pregnancy begins. They don't think you were pregnant on the first day of your last period, they know you were having a period! But if a doctor says "you're 6 weeks pregnant," he is she is saying "The size and developmental markers of the embryo we see in this ultrasound are consistent with an embryo of a woman whose last period began 6 weeks ago, and who ovulated two weeks later, or 4 weeks ago." They are not saying you are 6 weeks from conception. The reason the period is used to begin the count is that ovulation is hidden and can happen at various times in the cycle, but a period is a big, obvious signal. Not so long ago before ultrasounds, it was the only signal anyone had. So they would count from there, and count pregnancy as 40 weeks or 280 days long (even though it is actually only 266 days from conception to full-term birth). They added two weeks at the start, to back things up to a woman's first day of her last period. As I said, doctors, nurses and all (even you, once you get used to it) will use that count very naturally, and this means they sometimes forget to tell a woman who is worried about having more than one candidate for dad, that this is the counting method they use.
The reason this matters is that you should keep in mind that when a doctor gives you a number of weeks pregnant, when wondering when you conceived, you would subtract two from that number. When the doc said you were 6 weeks 4 days along, you were 4 weeks 4 days from conception. When the doc says 7 weeks along, it's 5 weeks from conception.
Anyway, don't worry about the guys of March. The guy of April is the one who is the dad.
Thank you for your reply for some reason the NHS nurses here seem to be a bit cagey about telling me the date they think I conceived I'm not sure why but I've come across three nurses who had all told me its too difficult to tell me if it was march or april.
Thanks again for your help much appreciated,