Watch how a sperm fertilizes the egg and divides DeoxyRiboNucleicAcid (DNA) you will eventually understand why conception is just as important as birth, you CANNOT be born without being conceived, there's no such thing as immaculate conception (otherwise jesus wouldn't look human.... Or white) Open your eyes people... Yes everything could go wrong in the womb, but it's the process that's the most interesting.
Why should we celebrate both is because if you really think about you're technically close to a year older than the day you came out of the womb. And both are important but we celebrate the day we get out of the womb because if a baby is a fetus and the fetus itself gets murdered nobody is held accountable unless you give me a case like that and tell me who won if the fetus won tell me if not then don't bother, according the law(man's law) a fetus isn't a person until it is out of their mother's womb.
I agree that a birthday is a special milestone that is worthy of being celebrated. However, a day of conception is just as (if not more important), as that is when a life actually begins. It should be called "life day". If you do not know the exact date, subtract 40 weeks from your birthday.
Not everyone knows when they were conceived, nor do their parents.
The thing is, from conception, things can go wrong. Complications can happen, the mother could get very sick, there could be a miscarriage or a stillbirth. A mother might need to abort, should their life fall into danger.
I think the birthday is good and that's why we celebrate that. It's basically saying 'you made it into this world safely, despite the risks of being in the womb and the risks to your mother carrying you, we'll done to you both.'' That should be what's celebrated. The anniversary of your birth after a daunting pregnancy where it's unknown what could have possibly happened.
It recognises the day you became an autonomous person, hopefully without any hitches, and that's why we don't need a day to celebrate your conception.
Not to mention, we don't really need the Pro-life focussing on something else to prey on in order to impose their opinions on others' freedoms.
How about the day your mom found out she was pregnant day? You celebrate that with a game where you pick a strip of paper out of a hat, and if you pick the blue one, someone hits you in the head with a brick. (A fake one, to symbolize how ol' mom felt.) Life Day? You celebrate that with another game, where you throw 250 million pieces of string in the air and try to catch one through the eye of a needle.
Read the top line, that's the main point. Conception is an important part but why celebrate it? It's the fact that you're out of the womb, then your life begins. Your life doesn't truly start at the point of conception... Because really, you're not even a fetus at that stage. But if you want to, go ahead. No ones' going to stop you.