Larger bulge than normal right under 5 weeks

Pregnant with 3rd baby... went to first dr appointment at 4w+5d. My doctor did the pelvic exam, and when he felt on left side, he was very surprised that He felt a bulge larger than normal. I asked him if that was normal and he said he wasn’t worried about it but it’s not very common this early on and he’s seen it before. I do have my first ultrasound coming up in a week and half so right under 7 weeks and I guess we’ll find out then. Just curious if anyone else experienced this. I had symptoms extremely early on before my positive test and still having cramping and extremely sore boobs. Could this be a sign of twins? Thanks!