The most important thing is to take responsibility. If you are both in a position to support a child, you can start making plans for the future. But if not, you need to look at all the available choices. You also need to think about how this will affect your families and friends. It's not just about you two anymore. You have to be prepared for a lot of changes in your lives.
First, you should confirm the pregnancy with a home pregnancy test or by visiting a doctor. If it's positive, then start taking prenatal vitamins. And think about whether you are ready to be a parent or consider other options like adoption or abortion depending on your situation.
You should start taking good care of yourself. Eat a balanced diet, rich in fruits, vegetables, proteins, and healthy fats. Also, begin taking prenatal vitamins if you haven't already. And, of course, inform your partner and start preparing for the changes that are coming, both emotionally and practically.