Hi I am new to this, I used 1 muntons beer kit and did not use any any other corn sugar or dextrose,It has now been 2 days and there has never been any bubbles in the air lock, but there was foam that came up left a ring on the inside of the bucket and has now completely disappeared and it seems that nothing is happening. I also forgot to take an initial hydrometer reading, but just took one it was 1.018. Is this normal and is my beer still fermenting?