Weird bites on my arm?

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I woke up this morning and my one arm was very itchy. I started scratching it only to realize there was about 3 or 4 larger bumps. I think it may have been a spider bites. I had just washed my bed sheets and hang them outside to dry (I love the smell and crispness of it) plus with winter coming this will be one of the last times I do it. I put some cream on it which helps with the itchiness but from me scratching it, it's now all red and swollen.