Maternity Wedding Lingerie

Hi. I hope you can give me some advice.

I bought my dress before I became pregnant. I will be in the middle of my 6th month when I get married.

The alterations lady I have will be able to alter the dress I have, but I'm having problems on what to wear under it. I can find a slip that will fit but having trouble with the bra, my dress is strapless. Are there strapless bras, that you know of, for pregnant women that give good support? Or should I have the bra built into the dress? Or should I have straps put on so I can wear a real bra (my last option)?

Any advice you can give me would be a lifesaver. Thank you.