Hello, I would be happy to help you with your question.
If you had conceived 3-4 days ago, you would NOT be getting pregnancy
related symptoms yet. That being said, given your symptoms, you must check a pregnancy test now and repeat it in 2-3 weeks. These symptoms are likely just related to your irregular cycles. These symptoms are typical in the 1-2 weeks leading up to your cycle.
I hope that this helps and good luck!!