I have looked into SSRIs and TTC before - quite a bit - and its a difficult area - which SSRI were you taking and how well was it working out for you?
inadequate seratonin is supposed, according to Dr B, to inhibit bloodflow to the uterus, but its my understanding that not many SSRIs actually boost your serum level of seratonin - they may work by totally different mechanism to what used to be thought - and in any case, some recent studies show that they don't actually work any better than placebo for a lot more than half of the patients who take them - and the bloodflow to the uterus theory seems to have been incorrect as many SSRIs (and 5HTP) seem to be associated with low birth weight babies in published studies- which implies growth restriction and some level of fetal distress i.e., inadequate bloodflow to the uterus in lab animal experiments - some of them have shown increasingly to negatively affect baby too e.g., paroxetine and venlafaxine have been associated with increased risk of fetal heart defects - they also seem to be associated with metabolic changes e.g., increased insulin resistance (leading to weight gain) which also isn't ideal for fertility - so before you take 5HTP or St Johns Wort or anything else, you'd ideally like to be absolutely sure there would be no negative effect on baby either physically at birth (which is easier for the docs to study), or mentally/moodwise in the long-term - which of course is pretty difficult for studies to show because it takes a long time - has your doctor been able to assure you that 5-HTP would be safe/benefit outweighing risk if you got pg?
there are gadgets and gizmos that are supposed to be at least as effective as SSRIs without any risk to baby e.g., electrical widgets that zip TINY (not to be confused with ect) microcurrents or magnetic fields through your body or through your head - some major hospitals have machines to do this now, but not many - especially for pg patients
i'm well aware that sometimes the benefits of ssris and similar drugs outweigh the risks and some people do need them - and i'm sure there are much worse things baby could be exposed to e.g., smoke, but when you stop after using them for a long time its possible to feel yuck due to discontinuation syndromes i.e., withdrawal effects and this can sometimes make you feel that you need to back on something even if the drugs weren't actually benefiting you positively - there are supposed to be strategies for managing discontinuation which are basically slow tapering off the drugs whilst you do increasing outdoor exercise etc - i seem to think there are some charities with volunteers to give you phone support to do this
do you eat plenty of oily fish? e.g., mackerel/sardines (not tuna, swordfish or other long-lived oily fish)
do you eat plenty of red, orange and green veggies?
Oats?
taking vitamin D3 at least 25 ug?
getting outdoor exercise everyday?
good quality protein intake most days?
just thinking of the lifestyle factors that are supposed to help manage seratonin.
but to go back to your original question - 5htp supplementation and ssris both do have effects on the immune system but studies seem to be mainly on rats - i did find a hint in this one that they might not interfere in a positive (anti-inflammatory) rather than negative way but i'd be cautious about implying that for all patients e.g., the patient group were described as 'healthy' implying they had normal cytokine ratios immunes to begin with - rather than, say, elevated (i.e., problematic) ratios
http://journals.lww.com/psychopharmacology/Abstract/2001/04000/Anti_Inflammatory_Effects_of_Antidepressants.12.aspx
sorry if this is all very negative but i am probably a bit biased on this topic