There are levels of hypomania. From what you have described you are on a lower level, which is great because you will most likely have fun, accomplish more than usual, be more sociable and not do yourself or others harm. The only downside is the depression that follows, and even with a mild hypomania the depression can get real bad and last a long time if untreated.

On the other hand hypomanic can become more destructive; you become very irritable which leads to arguments, road rage, recklessness etc; you can overspend in sometimes grand ways and place yourself in huge debt; you talk so fast others cannot understand you and/or cannot stand being in your presence; you become grandiose as you head into mania and begin to think you are indestructible, invincible and even a special person. This of course leads to many problems.

I am sure I have missed things but after that list you tend to be heading into mania and need immediate intervention. One error a lot of people make is that hypomania is harmless. Getting yourself in massive debt, losing friends, possibly getting a police record for drugs etc can be lasting and damaging. So the best thing to do is that when you feel even mildly hypomanic put into place a plan to do your best to prevent it from escalating. If you don't have a plan ask you psychiatrist or therapist. This has saved many times.

Again, even mild hypomania can lead to crippling depression so try to get on top of it ASAP.