Congratulations! How exciting! Sorry I didn't see your post earlier. Hope this reaches you in time.
Most complications, including prematurity, with twins happen from malnutrition. Be sure you are eating enough protein & green leafy vege's. If you start swelling, increase your protein. Avoid junk food and empty calories, make every calorie count! The three of you need lots of Protein. In this hot weather, it is easy to want it all to be over, but patience is a virtue, every day they stay inutero, the safer it is for them to come out. The C/s rate is climbing at an alarming rate, hardly any twins are born vaginally anymore, but remember, vaginal births are usually safer than C/S, even for twins. It is safest if at least the first one is head down. If they are not in an optimal position, have a Chiroprator do the Websters technique on you before resorting to surgery. And did I mention how important PROTEIN is? Oh yeah, too much caffeine can stimulate contractions, so that should be kept to a minimum, if not avoided altogether. Dehydration also causes contractions, so drink lots of water during these hot summer days along with the protein.
My daughter had twins, naturally 8 months ago. The first was head down & the second was transverse, but came out breech after his brother came out and gave him room to turn. When she got to the hospital she was already 9 cms, having had me as a monitrice for the ten hours of labor up to going to the hospital. She was there for two hrs before they were born, one minute apart! They tried their darnest to get her an epidural, but she steadfastly refused. Don't go to the hospital without a monitrice or at least a doula! Their moral support & back rubs are invaluable!
There are many good twin births on Utube, my favorite twin video is "The Birth of Psalm & Zoya" by Mindy Goorchenko. She makes it look so easy... kneeling on the bathroom floor, catching her own babies, even the breech! It was an unattended birth, they planned to have midwives there, but the babies arrived before the midwives! Mindy was herself a doula & midwife's apprentice at the time of those births.
Remember, God never gives you more than you can handle! He must think highly of you to give you twins with two big "helpers"! Enjoy!