Calcium tab does not cause dizziness,or pain,or frequent defecation.but if you are having these,it can be due to some other causes.like if you are taking iron tablets,or progesterone tablets or it can be due to preterm uterine contractions.
Next Steps
1.consult a gynaecologist.she will help you to find out the cause and treat accordingly.
2.take proper bed rest for few days.
3.you can switch to other brand of
calcium,or can take syrup or sachet.