Could it not also be a possibility that this is an unplanned pregnancy?
She could have agreed to the fertility collab simply because as she said, she's aware it's an issue for a lot of people including friends of hers and wanted it to be openly discussed.
Maybe she didn't realise she was pregnant at the time she signed up to the collab.
Some of the choices she has made recently doesn't seem to have had a baby in mind, such as buying the camper van for example.
She has almost completed her college assignments which I assume is to further her career.
She has been talking non-stop throughout the pandemic about travelling again with David.
I realise these are all things you can also do while pregnant or with a baby/toddler.
I just personally think it may have been unplanned and so to cover their disappointment that all their future plans will have to change, they are going to extremes to show how thrilled they are by filming that over-the-top video of them hugging!
I'm sure when they get over the shock of it, they will be delighted and make new plans as most expectant parents of an unplanned pregnancy do.
But that's just my take on it all. I could be completely wrong of course .... but just throwing out another angle to look at it from, that's all.