Cramping BADD

So my period isnt due to start until 8/15(according to Ovia) or the 8/20 (according to glow) since 8/5 ive been getting intermittent cramps that started off just dull n more uncomfortable than painful, since 8/8 untill today 8/12 the cramps are still intermittent but are getting more intense n painful, no blood, heavy discharge, tender boobs, might be my imagination that my nipples are darker, n I've noticed the veins are more pronounced in the areola n down my legs, I've been super tired, hungry more, nauseous in the morning n at night, indigestion has been bad, n I've been moody, well today so far every time I stand, use the bathroom, n jump up(I'm watchint my 2 year old n my 1 year old nieces) I get period like cramps for not even a minute then it goes away. Soooo anyone else experience this?