help plants are dying

My plant are in there 2nd week of flower three of my plants the leaves are turning yellow in a matter of days dying two are ready bad please help

sounds like nitrogen deficiency. Not sure what nutrients you are using or if its soil or hydro, but sometimes people only give flowering nutrients during flowering and sometimes these nutrients have basically zero nitrogen. I would look into getting a line of nutrients that have a feeding schedule if you aren't used to growing. Early flowering it is perfectly fine to give more nitrogen than late flowering. Then the last couple weeks flush the soil with water only.