It's your subconscious that is worried that you will break up with your boyfriend. Dreaming about a sedan chair is usually your intuition. Your boyfriend may have another woman, or another girlfriend has a very good relationship with him, which makes you super unhappy, worried that he will cheat, or have two feet on both sides. This is not a good dream, and women's intuition is often more accurate.
Having such a dream shows that your relationship with your boyfriend is on the verge of breaking up. Very dangerous.