Something stuck in foot???

Charity
So last weekend, I went to the beach and got into the water and stepped on something sharp. I immediately felt my foot and felt a small bump, but didn't feel anything sticking out of it. I walked back to my beach chair and didn't see anything, and it didn't hurt to walk or anything so I just went about the day. All week it hasn't hurt, and I haven't  thought about it since the beach until yesterday! Yesterday I went to the mall and walked around for about an hour, and when I got home I noticed my foot was hurting and suddenly I had started to limp a little because pain was getting a little more noticeable. I sat down and checked and felt the small bump and then immediately remembered what happened at the beach! So now I'm on day 3 of limping around and I'm not sure if I should go to the doctor or what? If I do go to the doctor, what doctor do I see??? I'm 32 weeks pregnant and just want some advice. I don't have a primary care Doctor set up. So wasn't sure what to do in this situation.