Trying for a sibling and not getting pregnant immediately is completely normal. Two months isn't a long time, so there is no need to worry too much yet. To increase your chances, you should track your ovulation period, have sex during that time, stay healthy, and avoid stress. Additionally, the partner should be healthy as well. 

Contraceptive pills can produce side effects such as nausea, dizziness, and fatigue. It doesn't mean that you are pregnant when you have these symptoms. You can still use a pregnancy test after a few days if you are anxious. Be sure to drink enough water and sleep well to recover your health.

When periods are delayed and prolactin levels are at 28 ng/mL, it may be due to a condition called hyperprolactinemia, which is characterized by high levels of prolactin in the blood. Symptoms can include irregular periods and milky discharge from the breasts. This condition can be caused by stress, certain medications, or a benign tumor on the pituitary gland. Treatment usually involves medication or addressing the underlying cause.