Any swelling especially if it is accompanied by it being one limb or leg etc redness swelling or pain warrants a check of your bloods and running a d- dimer blood test. I know because I have a blood clotting condition and am on blood thinning injections and have had a fair few tests for clots including a vq scan which isn't pleasant if a clot moves. I would get checked as your higher risk pregnant. Don't want to scare u but I would go in with that totally! Too many ladies get these things and it can be easily treated with injections in a bit higher dose than I take.