Should I buy a bigger cup size?

Okay so I usually wear a 32C.
I have a bra from Calvin Klein and the C is way too tight-my boobs like fall out. Lol. But it’s not tight around the band… And I have a Frederick’s bra in which a 32C I barely fill in, I think because it’s probably a full coverage though. I want to buy another Calvin Klein bra but I don’t know if I should get a 32C or 32D? I have been measured and yeah my size was 32C, but I heard that Calvin Klein runs big? o.O
Thanks.

The best thing when buying a bra is to try it on. I know depending on the bra I can fit from 38C to a 40D.

Calvin Klein Seductive Comfort Customized Lift Bra 34C $9.99

Women Calvin CK Klein Cotton Bra UB A01 Panty Size M $0.99

Women Calvin CK Klein Cotton Bra UB A01 Panty Size L $0.99

Women Calvin CK Klein Cotton Bra UB A03 Panty Size M $0.99

CALVIN KLEIN NEW BRA 14D/36D $20.21

CALVIN KLEIN PUSH UP BRA sheer lace 34D Thong Med NWT $39.99

CALVIN KLEIN Perfectly Fit BALCONNET Bra 38B XL Bikini $43.99

CALVIN KLEIN Size 34B Nice Nylon Print Bra Underwire $3.25

CALVIN KLEIN "Petites T-Shirt" Bra 36B Bikini NWT $41.99

Super Sheer Super Sexy Calvin Klein Body Suit/Bra 34 B $9.99

Calvin Klein Bra(36B) & Thong(L)"Midnight Purple I" NWT $21.95

CALVIN KLEIN BEIGE PUSH UP BRA...NEW sz 32A #12789 $9.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

New CK Calvin Klein Contour Bra F2710 UW Molded Cup NWT $29.99

Calvin Klein (Sexy Bra Ad) Lobby Card Art Postcard Print - 4 x 6 $1.99 ...

Bra Sachet Gift Set $35.99 This bra sachet gift bag is perfect for the person that has everything. The bra sachets are great to put in lingerie drawers or the car. The lingerie gift bags can be reused for personal items or lingerie traveling. Please note that the lingerie gift bags may be a different color than pictured. There are only 2 assorted bra sachets in this gift. The picture is showing the different colors of the b...

Calvin Klein Women's Perfectly Fit Tailored T-Shirt Bra $44.00 From the new & improved "Perfectly Fit" collection, this gorgeous bra enhances your figure under t-shirts & sweaters, making it perfect for daily wear. Crafted in smooth microfiber by Calvin Klein....

Calvin Klein Women's Seductive Comfort Customized Lift $44.00 A beautiful bra tailored for you: the Calvin Klein customized-lift design provides the perfect amount of support for every cup size. Style #F2892...

Calvin Klein Women's Seamless Edge Thong $12.00 Smooth and seamless, this hipkini by Calvin Klein will keep you comfortable all day long. Style #D3317...

LES METHODES DE TRAVAIL DE GERSONIDE ET LE MANIEMENT DU SAVOIR CH ...

Calvin Klein Women's Calvin Klein Dot Print Retro Bra Swimsuit Top ...

Calvin Klein Fudge Perfectly Fit Swimsuit Top 36C $39.00 72% nylon, 28% lycra liner: 90% nylon, 10% lycra...