Exactly two weeks since conception. Severe Nausea, bad abdominal pain, fever. For 1 week- 1 week after conception. Is this pregnancy related?

Nope. Nothing that happens in the 1st 2 weeks after conception is pregnancy related, it's too early for any symptoms. Certainly not bad abdominal pain or fever. You didn't say: are you actually pregnant? Did you have a positive pregnancy test? Good wishes.