The text Bates gets - Is Rena pregnant?

What would cause Bates to have such a temper tantrum in next week's episode? He makes Matt promise not to tell anyone. The only thing I can think of is that his ex-girlfriend, Rena, is pregnant. Or, maybe another girl he cheated on her with is pregnant. What else would make him so upset? His family may have gotten shunned or shunned him, but why would he make Matt promise not to tell something like that? Maybe Rena is marrying an Amish man; but, again, why would he make Matt promise not to tell? Any other theories?