Tax refund

I’m trying to figure out why my tax refund is taking so long. I filed mine on March 4th and I filed my boyfriends March 13th and he already got his back. We filed with the same company but I still have no gotten my refund. His was $700 and mine is only $400. Every time I check my status it says “your refund is still being processed. A refund date will be provided when available. I e-filed same as him and so it shouldn’t take more than 21 days. He got his back after a week.