TTC 1st baby after brain surgery!! So many questions, please help!

Hi everyone! I'm 26 and have just had major surgery to remove a tumour from my brain, which left me having seizures 5-6times a day, crippling headaches, blind in one eye, unable to sleep and with VERY irregular cycle 68-120 days long (among other delights!) 
The tumour was removed successfully and after learning to walk again and coming quite so close the the reality of mortality my husband and I decided to just go for it!! 
We have been trying for the past 6weeks and I am currently 3 days late for AF after having my first 28 day cycle in over a year last month. I did a test the day I was due on, which came out negative, but I am having some strange symptoms that I don't know whether to put down to the healing process after the op or let myself get my hopes up about being pregnant - these include - nausea, headaches, severe tiredness, cramping and backache, random spotting, severe heartburn and hiccups - I don't know if anyone else experienced any of this during early pregnancy and should I just go to the doctor and do a blood test?
Any advice would be great, after what we've been through recently were just hoping to start our own little family and I don't want to get too hopeful too fast!!
Thanks 😀