I'm afraid of pregnant women

Whenever I see a pregnant woman I get goosebumps and feel like I'm going to be sick. My friends told me that I also grow pale and look fainty.
Also, I get really weird thoughts: I keep thinking "what if she falls? what if she falls on her belly and it explodes? what if she falls on something pointy and punctures her belly?".
I know it doesn't make any sense, and I do realize that none of that is possible: still, when I see pregnant women, that is what comes in my head.
Once I was grocery shopping and I was in a very narrow aisle when I saw a pregnant woman approaching. I tried to make room for her to pass and become as little as possible even though I felt like running away and screaming but as she accidentally touched my back with her elbow. I felt like I was going to faint and I kept thinking she could fall and it would be my fault.
This phobia makes me socially awkward so I keep it a secret but in facts it's pretty noticeable.