😫Help!

So confused. My app says I'm just about 5 weeks based off my last period. But I know when I ovulated and I'm really just 13 DPO. Got my BFP yesterday. Feeling super nauseated in the morning. Can't stomach anything. Clears up in the afternoon, but I do feel so tired. And no appetite in general. I feel like I'm getting weak. My husband says it's anxiety and fear of morning sickness, but this feels real. Isn't it too early? Does this mean I will end up really ill a few weeks from now? Anyone start of feeling super bla, and actually have symptoms not be too terrible the rest of the first trimester?