How do i find out if my phone is sending duplicate messages to a friends phone?

[AC Question]

My boyfriend says every time I send him a text message, the same message comes in as one message & then again in multiple pages, especially if it says more than one page on my message

 

[B. Diddy]

Welcome to Android Central! What do you mean by multiple pages? Are these long messages, more than the 160 character limit for an individual SMS message?