Painful cramps with no bleeding at the end of AF!

Revathy
Hi all, I m ttc #1 for the past six months . My periods cycle nowadays is like this: 
​1st day: spotting with no cramps 
​2 nd day: medium flow with severe cramps 
​3 rd day: heavy flow with severe cramps
​4 th day: spotting with severe painful cramps
​5 th day: very very painful cramps with no bleeding at all! 
​Usually on my 4 th and 5 th day cramps wud go away . I don't know why is it changed like this now. Is this something dangerous? Pls I need help.