The baby is angry / crying while having tummy time. That’s why I don’t put the baby on his/her tummy. Is that bad? 
I am confronted with this situation „n“ times, and until today have to consult parents quite often. The problem is that parents usually repent of their baby when they start showing emotions and decide not to put on their tummy, although this is very important for baby’s head control and not only for that.
You should try to change your baby’s sleeping position from the first weeks onwards and try to have tummy time – not only your neck, head and hand support will be strengthened, but also your back muscles, your baby’s sensorics, coordination and etc., (more in the picture), also it’s one of the ways to prevent plagiocephaly.
* Plagiocephaly 
This is a deformation of the scalp when one part of the head is flatter. Because the baby’s skull bones are not stiff yet and are moving, there are pulsating fontanelle between the bones (grows up and ossify after 2 years). Therefore, the head can only deform while lying on the back of the baby without changing the sleeping / feeding position.
What will happen if you don’t take the baby tummy time seriously? 
The baby’s neck, back muscles will be weak, the baby will not hold the head, and will not support the body weight with hands, it will affect and delay motor development. If baby doesn’t want to be on the tummy, you will not see the baby initiative of crawling, so be aware that having tummy time affects not only the strengthening of the neck muscles, head control, prevention of plagiocephaly, but also the further development of the baby’s movement.
How long does a baby have to lie on a tummy? 
The trick is that the earlier you start practicing to lay baby on the tummy, the faster it gets used to it and every time it will be longer. It is very important when the baby lie on tummy – to engage with the baby, show a favorite toy and then the baby will be more motivated to keep his head up.
• At the end of the first month, the baby should lie on the tummy about 30 minutes per day.
• At the end of the second month ~ 50-60 minutes per day.
• A three-month-old baby should lie on the tummy for about 1-1.5 hours a day. 
True, it’s a lot! However, you can add the baby tummy time to your daily activities, do it in different positions, such as carry along or when you have baby on your chest (this is a favorite position for babies) and etc.
The baby’s tears, anger, may appear – it is normal, they will really show emotions. 
The baby can not say that – Mom or Dad, I don’t want the tummy time, they express dissatisfaction through emotion, try not to be pity with the child, he/she must go through this. In Lithuania says: through suffering to stars 
So, be strong moms and dads, let the baby be emotional – it’s healthy. You can get replies from family members like you “torture” your child, and so on. However, this is not true and you do not need to think that you are a bad mom or dad, on the contrary – you care about your baby and his/her further development 
Keep going