Basically anything related to eco-friendly menstruation is the main focus of the site.... but anything relating to menstruation, empowering women or even female needs can be appropriate. You're certainly not limited to cloth pads.
This list of ideas shows the types of things that could suit the site, and may give you some ideas of products you could add to your store.
Cloth Pads and Pantyliners (for menstrual, Post Partum/Post operative or Incontinence use)
Cloth Nursing/breast Pads
Mattress protecting pads (for breast feeding, menstrual, post partum/post operative use or coitus)
Cloth Wipes ("reusable toilet paper" for freshening up), and containers/bags for them
Wet bags (waterproof bags for carrying clean/used pads or cups)
Storage or carrying bags/containers (what you might use to keep your pads in between use. Bags to hang from the back of the bathroom door, nicely decorated or fabric covered storage boxes etc.)
Menstrual cup pouches/wetbags
Pad/Cup washing solution (natural preferred) - includes soapnuts, stain removers, soaps etc.
Soaking pots/containers, including things like large drawstring bags to cover buckets/containers that are used as soaking pots.
DIY stuff - PUL and other fabrics in small or large amounts people can buy for making pads, patterns (you can buy patterns to resell, or write up your own pattern to sell) including hand dyed fabrics if you like
Gift boxes of cloth pads etc. for people to give as gifts
Gift vouchers for your store
Women's diaries and menstrual cycle charts
Books on menstrual topics, pregnancy or feminine empowerment
Menstrual/Feminine need related herbal teas (ones good for cramps, PMT, pregnancy etc.)
PMS/cramp relieving type essential oils or massage blends
Menstrual or feminine empowering art (paintings, prints, pottery, sculpture, fibre arts etc.)
Jewellery - preferably with red colouring, or with feminine symbols (pregnant women, goddess symbols etc.)
Handbags/totes with matching wetbags
Chocolate ;) Including ideas such as selling packs of nice teas and chocolates for Aunt Flow's visit.
If you have ay other product suggestions, or you'd like to stock something that isn't on this list, please contact email@example.com