I remember searching the same thing when we were planning! Search for "fertilization to birth 3D animation" on YouTube. It is so fascinating to look back at that miracle now that my little one is running around.
There are free medical animation videos on YouTube that explain fertilization perfectly. No need to buy any paid courses or apps for this basic info, save that money for scans and doctor fees.
Honestly, just typing "conception 3D animation" on YouTube will give you perfect, easy-to-understand videos. I watched them during my first trimester to understand what was happening inside me.
If you are looking to understand conception for medical reasons, please consult your doctor directly. They can explain it with proper medical diagrams instead of confusing online videos.
YouTube has very simple and respectful educational videos that show how a baby grows week by week. My mother and I used to watch those animations together, it's beautiful.
Having PCOS, I watched so many 3D animation videos on YouTube to understand ovulation and fertilization. Just search "how conception happens 3D" and you'll find very clean, educational ones.
Please don't watch those overly graphic birth videos, they used to scare me so much and give me sleepless nights! Stick to simple 3D biological animations of sperm meeting the egg.
You can find very clean scientific animation videos on YouTube. My elder sister suggested watching those instead of reading random blogs, it gives a very clear picture of how life starts.