AITA for walking away from my pregnant wife on the beach?

So we parked the car at the beach which is about 100 metres away from the sea and started walking up. My wife is almost 7 months pregnant and is quite a slow walker. I pulled ahead about 15-20 metres to get a lay of the land and to see how busy it was etc. My wife claims when I pulled ahead I didn't turn back to check she hadn't fallen over once.

I was not that far ahead, and I easily could have heard her if anything had happened. I think she is being unreasonable because it doesn't seem like a big deal. We have a very good relationship, we rarely fight but this seems to have really got under her skin.

AITA?

Edit: we're on holiday in a foreign country and it's significantly hotter than a temperature we're used to. I'm also 6ft4 and she's 5ft 1