If Your Baby Cries Initially During Tummy Time, Do Not Force Them
Your baby may initially cry while she is on her tummy as it is a new position. Ensure that your baby is comfortable and bring them back to their normal position if they are finding it unpleasant. You can always give them a chance later. The roll over state comes almost naturally and unannounced to an infant. The first few times they roll over, they may not realise it and get a little scared or worried. Also this position can restrict their breathing so they may get uncomfortable.
However, rolling over is an important step towards the infants getting on their knees and beginning to crawl so make sure that you put them in the habit of rolling over every now and then. After a few initial jerks, they get the hang of it and even enjoy being on their tummy every once in a while.