Colposcopy delay period ?

Hi there, I had an abnormal smear which resulted in me having to go for a colposcopy where I also had a punch biopsy. This was on the 14th of April. Since then I have not had a period, (last period started 1st april) I have took 3 hpt all being negative. Yesterday I had cold coagulation to treat the abnormal cells and I'm just wondering is there any chance I could still be pregnant or is it definitely the colposcopy delaying my period?!? Feel like my body is messing with me since I'm ttc and never had a late period before !