Feeling depressed and sad ever since my miscarriage

Do you think it's wrong for me to feel randomly sad and depress at times, I had a miscarriage in March, my fiance has two children from a previous relationship I love his children and I always look out for them but ever since my miscarriage I feel really sad when he talks about his children and when he tell me about friends who's wife's given birth etc I just feel really shitty at times and really sad each month when my period show up😣😣😣😣