Concerned

Im 17 weeks today and woke up not feeling pregnant at all . Yesterday i seen my stomach move from baby move and barely felt it but that was in the morning . Then today usually baby moves once i get up but havnt felt nothing at all. Im concerned i lost one baby in 1st trimester and i suppose to find out this friday the sex of this one . I cant go threw another loss at this time i have everything i need for this baby ready .i usually can put my hand on my tummy and poke the baby and it move but now it wont im very concerned Anyone else thinks im just stressing ? Has this happen to anyone else .