Worried😕 no temp rise after ovulation

I've been trying for 9 months and this is the 1st month I've not had a temp rise. I had a positive opk on Sunday with pains all last week then glow said I ovulated on Monday. Now 2dpo and no temp rise 😭 should I buy a new thermometer? My one is a cheap one off eBay! Really worried, don't need this change in my cycle 😭