Okay so I had my period dec 5 had sex dec 9 took after day pill the next day had unprotected sex again for about three days straight but got my period dec 17 for a week guess the pill gave me a second period that same month after that period I started trying for a baby took a pregnancy test on January 10 & came out negative on January 28 took another pregnancy test and came out positive and yes I'm pregnant now my wich would be my lmp ? My due date is on oct 3 at first they went by my lmp that would be 8 weeks or so when I had a ultrasound my obgyn change my due date to oct 3 so which lmp should I use or what happened ?

Dates are too close to tell. If you're worried about who the father is, you will need to do a DNA test when the baby is born.

There is no way to know your exact conception date... once you have an ultrasound the doctor can make a guess... and its just a guess that would be accurate to a 28 day period.

That means they make a guess that can be 2 weeks before to 2 weeks after.

If you slept with more than one man during that time.. the only way to know which the father was is a DNA test after the child's birth.

Dates are too close to tell. If you're worried about who the father is, you will need to do a DNA test when the baby is born.
But even if they go by my lmp which is dec 17 I'm like a week in a half behind so she change my due date baby was to small

It doesn't matter... that date is only an educated guess and they tell you it can actually be anytime from 2 weeks sooner to two weeks later.

That's 4 weeks... so anyone you slept with that entire month might be the daddy.

Just an FYI, Morning after pills are not 100% effective.

There is no way to know your exact conception date....once you have an ultrasound the doctor can make a guess...and its just a guess that would be accurate to a 28 day period.

That means they make a guess that can be 2 weeks before to 2 weeks after.

If you slept with more than one man during that time..the only way to know which the father was is a DNA test after the childs birth.
But with the fist one I only had sex one time and I don't even know if he came but I still took the day after pill and that have me a period for about a month I tried and tried and yes I got pregnant

#1. He doesn't have to finish... the penis leaks sperm the entire time.

#2. The morning after pill isn't 100% effective... you could have gotten pregnant before taking it and it didn't work. Likely... no... possible... yes.

#1. He doesn't have to finish.....the penis leaks sperm the entire time.

#2. The morning after pill isn't 100% effective.....you could have gotten pregnant before taking it and it didn't work. Likely... no...possible...yes.

Yeah I told her that I was like okay my first lmp was dec 5 she told me it can't be I'm not that far I'm only 29 weeks if I would go from my first lmp in case the pill didn't work I would be 32 weeks she change my due date in my first ultrasound I had no heart beat fetus was to small I'm just afraid of telling her what happened she said I ovulate late

#1. He doesn't have to finish.....the penis leaks sperm the entire time.

#2. The morning after pill isn't 100% effective.....you could have gotten pregnant before taking it and it didn't work. Likely... no...possible...yes.
They said the pill works when you get your period a week later and that happened to me had a heavy bleeding for a week ugh I'm just so confused and scared but thanks a lot

So... what are you wanting us to tell you? You already have the answer that you want, right? The doctor told you this and that and you're looking for what now?

Go by what the doctor said.

Like I said... when you ovulated doesn't matter. You are pregnant.. thats known.

You take the date they gave you... which is only a guess... and you will have gotten pregnant as early as 14 days before that date... to as late as 14 days after that date.

THey guess based on the size of the fetus which folows a predictible growth rate.

Baby Size Chart - Fetus Size Chart (http://pregnant.thebump.com/pregnancy/pregnancy-tools/articles/how-big-is-baby.aspx?MsdVisit=1)

Its more scientific than that... but this is in a way that's easy for anyone to understand.