Hi. I'm 40yrs Old, Female About 80kg And 1.74m In

Hi. I'm 40yrs old, female about 80kg and 1.74m in height. I recently developed a boil on my face just below the mouth, this in turn affected my tonsils and I was put on antibiotics : co-amoxyclav. I have since developed a blocked nose to the side of the boil. I don't know if this is a side effect but it happens whenever I use this medication. It's been 3days since I started on the medication. Please assist? Thank you.