I had tonsillitis twice in early pregnancy. I left it two weeks before going to drs and made myself quite ill with high temps. It's fairly easy treated and I had two lots of antibiotics that were deemed safe in pregnancy. Can't remember what they we're to be honest it might have been flucloxacillin or ciprofloxacin. I'm 37 weeks now and baby is doing fine. I was also told to gargle corsodyl mouthwash. Tonsillitis makes you feel crap and I had the white blobs which I was told was my tonsils discharging pus. Shame there isn't a puking icon.
It sounds odd but I always found gargling with dispirsable paracetemol. spitting it out, not swallowing, it helped get relief to the right area. I had tonsilitus recurrently through my last pg and GP recommended it.