Hi,
Welcome to ehealthforum.
Having tender nipples and soreness in breast is one of the signs of pregnancy. Look out for other symptoms suggesting pregnancy like: sore breasts, headache, nausea, increased fatigue, tiredness, sleepiness and hunger, mood swings, constipation, increased frequency of urine, abnormal or missed periods and lower abdominal cramps.
Report to your healthcare provider/gynecologist if any of these symptoms are present for an examination and tests to confirm the pregnancy.
Take care.