Note: If you’re not sure what your Rh factor is, you can know by your blood type. For instance, if you’re O-negative or O-positive, that “negative” or “positive” is referring to your Rh factor. Don’t know your blood type and expecting? No need to worry; your doctor will test your Rh factor as part of the routine blood work. Photos: 25. ANKAWÜ via wikimedia commons, 24. Tim.Reckmann via wikimedia commons, 21. Panthro at English Wikipedia, 20. John Nakamura Remy via flickr, 18. businesswire.com (fair use: illustrative purposes only), 17. NIAID via flickr, 15. healthprose.org (fair use: illustrative purposes only), 13. thefertilechickonline.com (fair use: illustrative purposes only), 12. diverdave via wikimedia commons 11. theodoredalrymple.wordpress.com (fair use: illustrative purposes only), 10. Tom Varco via wikimedia commons, 9. Vaprotan via wikimedia commons, 8. melvil via wikimedia commons, 7. Intropin via wikimedia commons, 5. Intropin via wikimedia commons, 4. Jeffrey Beall via wikimedia commons, 3. User:Tirante via wikimedia commons, 2. Gonegonegone at English Wikipedia, 1. Blausen.com staff. “Blausen gallery 2014”. Wikiversity Journal of Medicine. DOI:10.15347/wjm/2014.010. ISSN 20018762.