How many times can someone cancel plans last minute on you before you get upset?

Ive had a friend and her boyfriend cancel plans on me last minute 4 times now. The last time really hurt my feelings. I had went out to the store and bought food and drinks because they were supposed to come over and see us before they move across the country. I had food in the oven cold beer and drinks on ice and was patiently waiting. They knew this as we had discussed which food i should buy and what drinks they like. I heard I got a text and assumed it was them asking me which house is ours or something and it was instead a text saying they haven't even left yet and are no longer coming because it started snowing. My friends boyfriend is not a native to our state and she says the snow freaks him out. But it has been so warm that the snow wasn't even sticking to the roads and it was just making them wet. I was crushed because it was the fourth time they cancelled last minute. The first time they cancelled because her boyfriend was too tired and my husband and I were already waiting for an hour at a bowling alley for them. The second time we waited at a bar for her to say her boyfriend had to stay late at work and cover someone else's shift. The third time was my son's birthday party which happened the day before the snow and the reasoning was again that her boyfriend was tired and they will come tomorrow. I'm trying to be understanding but I'm also due for my period any day now so I'm extra sensitive. I'm starting to think they just don't want to hang out with us but at the same time why would they keep rescheduling it if that was the case? Each time my friend is super apologetic and genuinely seems to feel bad. I know things happen and plans have to change sometimes but this last time really hurt. Am I wrong for being upset? Update: Thank you for everyone's responses. I like to give people the benefit of the doubt and I'm a very giving and forgiving person. I would give someone in need i didnt know the shirt off my back as the saying goes. A quality my husband says invites people to walk all over me 😶😶 It never occurred to me that her bf could be abusive as her ex was extremely physically abusive and it was hard for her to trust another person again. But since she's moving across country for this man and leaving everyone and her family behind I thought he must be the bees knees. Now I'm a little fearful for her.