Anyone fall sick easily when pregnant

This is my first pregnancy & in my 2nd trim and i realised that im more prone to falling sick now that im pregnant compared to before pregnant. Ive caught the flu bug like 3-4 times, keep coughing, even got covid for the first time. Worst thing, since we’re pregnant, we’re not allowed/advised to take any medicine, except for paracetamol (which barely works). Ive taken the flu vaccine fyi. Ive taken too many mc from work too 😭 Is it normal that our immune system is somehow lower when pregnant.