Definitely try to persuade your boyfriend to go with the foreplay a little longer. Sex isn’t the only fun part—foreplay’s awesome too, so show him that. Make him enjoy it as much as you do.
(Also, I’ve heard that the longer your foreplay lasts, the longer intercourse will last.)
And definitely pick up a bottle of lube. It could be the birth control affecting your natural lubrication (so if you like, it might be worth talking to your doctor about it) or you could naturally be a little less wet than necessary. Either way, there’s no shame in using lube. Quite the opposite, in fact. A good knowledge of lube—and having it available—demonstrates a sophisticated understanding of sex.
If you’re using condoms, make sure the lube you get is compatible. Water-based and silicone-based lubes should be safe—anything else could potentially weaken the condom. Water-based lubes are a little less gross, but tend to evaporate more quickly. I highly recommend Liquid Silk. It’s water-based, but lasts for a while. Wet is also a popular brand that I’ve used and it’s pretty good too.
But as @DrasticDreamer said, if lube doesn’t help, you may have another issue, definitely worth discussing with a gyno. Find another doctor—at least for their opinion on this issue—if yours isn’t helpful.