Many Feminine Protection products always have a way for you to give their products a try before you buy them, and many times they might even have a little trial package that allows you to sample several different products at one time.
Also, in many cases, when you've signed up for the sample not only will you get coupons for the products in the sample package, but you could also receive coupons in the email that you provided (use your deal email here) for future purchases.
Here are some current promotions:
Poise Pads : in this package you will receive a regular liner, a long liner, an ultra thin pad, plus a coupon - it doesn't say for which product is for, it could just be a general $$-off coupon for any Poise product.
Playtex Tampons : In here you receive 3 regular unscented tampons, plus you have the option to sign-up for Playtex emails for future product updates and coupon offers.
Kotex : They have the choice of three different sample packs so you can choose which is better for your needs:
Sample 1: 2 Regular Maxi Pads and 2 fresh and dry long liners
Sample 2: 1 Super Tampon, 2 Regular Tampons and 2 fresh and dry long liners
Sample 3: 2 Ultra Thin Pads with wings and 2 fresh and dry long liners
Kotex also, often, has coupons in the Sunday circulars so if you like their products, you can usually find them at Walmart or Target pretty cheap.
Always : They currently have a promotion to try their new Infinity pad and a different promotion to try their thin Flexi-style liners. Not sure if you have to choose which promo or if you can sign-up for both, but you can try. They also have a tool to do a product selector so you can choose which of their products would work best for you.
Tampax has a current promotion to try Tampax Pearl. You do have to register with P&G Everyday Solutions (they are the printers of one of the Sunday circulars), but it will send you emails about other deals and coupons as well, so it could be a good thing for those that are interested.
Stayfree often has free trials of different products, although they don't seem to have any at the moment. Currently they have a $1.00 coupon offer. They are someone to bookmark or sign-up for email alerts if you want to try their products.