I am having pretty regular contraction every 20 mins for pass 1 hr (Since 4 am). I was 2 cm dilated in the evening around 6 pm and had the bloody show at around 5 pm. Wondering if I should go into the hospital yet or wait for my water bag to burst? Or for contractions to be between 5-10 mins apart.

It sounds like your baby is on the way! Hospitals usually advise you to head down when your contractions are about 5 to 10 minutes apart because they will very soon be 1 to 2 minutes apart and by then, you will likely not make it to the hospital due to the pain. For me, my water bag didn't burst and was broken by the midwife, so it's not true that you have to wait for the water bag to burst before you head to the hospital.