42 Year Old, Trying To Conceive, Have Missed Periods, Nausea, Lower Back Pain, Odorless Discharge. Pregnancy Or Something Else?

I am 42 years old, very healthy and have been trying for a baby, I am now 11 weeks overdue for my period, negative urine test, first month nausea , now putting on weight have tender nipples lower back pain and often feel like my period is coming but nothing happens. 2 weeks ago had a bit of white odourless discharge . Could I still be pregnant or is there something more serious wrong?