Need advice please

I found this app after I had my implant taken out august 19th. I was already supposed to have a period and haven't yet but me and fiance have had intercourse the day after and for a couple more days and I haven't been feeling well. I feel nauseous, tired, cramping, dizzy and lightheaded at times, also headaches. It makes me wonder if I'm pregnant but I've taken 3 test and they all say negative. We are TTC again after having the implant for 4 years. My dr said the meds from implant wear off in a days time and I was supposed to start my period on the 20th. Any help would be appreciated.