help please!

my period is die in 5days according f this app. the last two nights when it comes to bed time i cant seem to get comfy at all...and when i go for walkes i cramp. this has never happend to me before. when i was pregnant with my daughter i got hella stretch marks on my belly and all of a sudden the last few days there hella itchy. and last week i got light headed doing dishes. and i had a emotional day. this has never happend like this before......help please.