Am I pregnant? I NEED QUICK ANSWERS

I am on the Nuvaring birth control and I do make sure I take it out every 3 weeks and put it in on the right day too, also making sure it is refridgerated, but recently I had gotten a bladder infection and was on antibiotics (Keflex to be specific) and I have finished the treatment, but I have been noticing that my lower abdomen is VERY hard right where my cervix area would be and I do feel very nauseous and VERY tired constantly. The nausea sets in sometimes, but I am always so exhausted even when I do nothing to get tired. I have a loss of apatite but my tummy will hurt if I don't eat. The thing is, if I am pregnant I need to know NOW because I won't have a period until January (because I get my period 2 times a year with my birth control) and I need to take this birth control out immediately so it doesn't harm the baby. Thank you guys.